This is not one of the names of the Messenger (peace and blessings of Allaah be upon him)

Firstly: 

The scholars strove to compile all the names of the Prophet (peace and blessings of Allaah be upon him) that are mentioned in the Qur’aan, Sunnah and reports, but they differed concerning that.  Ibn Katheer (may Allaah have mercy on him) said: 

There are many ahaadeeth about that – i.e., the names of the Prophet (peace and blessings of Allaah be upon him) – and the two great Haafizes Abu Bakr al-Bayhaqi and Abu’l-Qaasim ibn ‘Asaakir strove to collect them, and people wrote books on this topic, until some of them wanted to compile one thousand names of the Prophet (peace and blessings of Allaah be upon him). The great faqeeh Abu Bakr ibn al-‘Arabi al-Maaliki, who wrote a commentary on al-Tirmidhi called al-Ahwadhi, compiled sixty-four names. 

Al-Bidaayah wa’l-Nihaayah (2/252). 

Ibn al-Qayyim (may Allaah have mercy on him) said: 

The names of the Prophet (peace and blessings of Allaah be upon him) are of two types: 

1 – Unique names that he did not share with any other Messenger, such as Muhammad, Ahmad, al-‘Aaqib (the successor, i.e., the one who succeeds the other Prophets in bringing about good, or the Last Prophet), al-Haashir (the Gatherer), al-Muqaffa (the last Prophet, following in their footsteps) and Nabi al-Malhamah (the Prophet of Jihad). 

2 – Names whose meanings he shared with other Messengers, but he attained perfection therein, and he is the only one who attained perfection but he was not the only one who attained these qualities, such as Messenger of Allaah, Prophet of Allaah, slave of Allaah, al-Shaahid (witness), al-Mubashshir (bringer of glad tidings), al-Nadheer (warner), Nabi al-Rahmah (Prophet of Mercy), and Nabi al-Tawbah (Prophet of repentance).  

But if he is given a name for every one of his attributes, the number of his names passes two hundred, such as al-Saadiq (the Truthful), al-Masdooq (the one who is believed), al-Ra’oof (kind), al-Raheem (compassionate) and so on. Concerning this some people said: Allaah has one thousand names and the Prophet (peace and blessings of Allaah be upon him) has one thousand names. This was said by Abu’l-Khattaab ibn Dihyah, but what he was referring to was his attributes. 

Zaad al-Ma’aad (1/86). 

Secondly: 

After looking for these names, the scholars compiled them, but we could not find among them the name mentioned by the questioner, namely Maheen. Rather it is not possible for this name to be one of the names of the Prophet (peace and blessings of Allaah be upon him), because its meaning is not befitting for the status of a Prophet and Messenger. 

Ibn Faaris (may Allaah have mercy on him) said: 

Maheen means despicable or vile. 

Mu’jam Maqaayees al-Lughah (5/227). 

Thirdly: 

Perhaps the questioner has altered the name al-Muhaymin to al-Maheen. Some scholars listed the former as one of the names of the Prophet (peace and blessings of Allaah be upon him), and in some books it is miscopied as al-Maheen, but this is a grievous error.  

Those who included the name al-Muhaymin among the names of the Prophet (peace and blessings of Allaah be upon him) quoted as evidence the verse (interpretation of the meaning): “And We have sent down to you (O Muhammad صلى الله عليه وسلم) the Book (this Qur’aan) in truth, confirming the Scripture that came before it and Muhaymin (trustworthy in highness and a witness) over it (old Scriptures)” [al-Maa’idah 5:48].  

But the majority of mufassireen are of the view that the word muhaymin in this verse refers to the Book, i.e., the Qur’aan, and it is not a description of the Prophet Muhammad (peace and blessings of Allaah be upon him). 

Ibn Katheer (may Allaah have mercy on him), in his commentary on the phrase “Muhaymin (trustworthy in highness and a witness) over it (old Scriptures)”, mentioned three views held by the salaf: that it mean al-Ameen (the one who entrusted with it), al-Shaahid (the one who bears witness) and al-Haakim (the one who rules concerning its validity), then he said:   

These views are all close in meaning, and the word al-muhaymin includes them all. So it is trustee, a witness and a judge over every Book that came before it. 

As for that which was narrated by Ibn Abi Haatim from ‘Ikrimah, Sa’eed ibn Jubayr, ‘Ata’ al-Khurasaani and Ibn Abi Nujayh from Mujaahid, that they said that the verse “Muhaymin (trustworthy in highness and a witness) over it (old Scriptures)” referred to Muhammad (peace and blessings of Allaah be upon him), who was entrusted with the Qur’aan, it is correct in the sense that the Prophet (peace and blessings of Allaah be upon him) was entrusted with the Qur’aan but interpreting the verse in this way needs to be examined further. So to sum up, the former meaning is the correct one. 

Abu Ja’far ibn Jareer said, after narrating it from Mujaahid: This interpretation is far fetched with regard to Arabic language; in fact it is incorrect, because al-muhaymin is mentioned in conjunction with al-musaddiq (translated here as ‘confirming’), so it can only refer to that to which al-musaddiq refers.  

Tafseer Ibn Katheer (3/128). 

Fourthly: 

Our advice to you is to avoid both names: 

Al-Muhaymin because it is also one of the names of Allaah, may He be exalted, and it is not permissible to give people names that belong only to Allaah. 

Ibn al-Qayyim (may Allaah have mercy on him) said: 

Among the names that it is forbidden to give to people are the names of the Lord, may He be blessed and exalted. End quote. 

Tuhfat al-Mawdood (120). 

The same applies to the name al-Maheen, because it carries meanings of humiliation, lowness and insignificance, and the Muslim is proud of his Islam, noble in his faith. The Prophet (peace and blessings of Allaah be upon him) encouraged us to choose good names in the hope that their owners would attain the noble attributes referred to thereby. 

Ibn al-Qayyim (may Allaah have mercy on him) said: Rarely do you see an ugly name but the one who is given it is ugly or bad. Allaah in His wisdom has decreed that people will be inspired to give names that befit the object named.  

The Prophet (peace and blessings of Allaah be upon him) said: “May Allaah keep Aslam safe and sound (saalama) and may Allaah forgive (ghafara) Ghifaar but ‘Usayyah have disobeyed Allaah and His Messenger.” Agreed upon. These were Arab tribes whose names suited them. To sum up, ugly attitudes and deeds dictate names that suit them. Just as that applies to descriptions, it also applies to names of people. The Messenger of Allaah (peace and blessings of Allaah be upon him) was only called Muhammad and Ahmad because of his many praiseworthy attributes. Hence the banner of praise (al-hamd) will be in his hand and his ummah are those who give praise, and he is the one who gives the most praise to his Lord. Hence the Messenger of Allaah (peace and blessings of Allaah be upon him) enjoined giving good names, and he said: “Choose good names.” Narrated by Abu Dawood but its isnaad is da’eef. The one who has a good name will feel shy because of his name and his name may motivate him to do things that suit it and avoid things that are contrary to it. Hence you see that most of those who are vile have names that suit them, and most of those who are good have names that suit them. And Allaah is the source of strength. End quote. 

Tuhfat al-Mawdood (135). 

See also the answers to questions no. 7180 and 1692. 

And Allaah knows best.