Is the one who kisses a non-mahram woman regarded as a zaani (fornicator or adulterer)?

Firstly: 

What you did by kissing and touching this woman is a reprehensible haraam action from which you have to repent by regretting having done it and resolving not to go back to it. You also have to keep away from the things that lead to fitnah, such as mixing, being alone with a woman, and haraam looks. You should praise Allaah for having saved you from falling into the major sin of zina for which Allaah has issued a stern warning of punishment in this world and in the Hereafter, which includes the hadd punishment of stoning the zaani to death if he was married and giving him one hundred lashes if he is not married. 

The Messenger (peace and blessings of Allaah be upon him) told us that zina is one of the reasons for which people will be punished in their graves, and he has told us of the horrific nature of this punishment. See the answer to question no. 8829. 

How audacious this woman was when she transgressed the sacred limits set by Allaah, called you to haraam, sought evil and indulged in sin without any fear or shame. How great is the blessing of Allaah to you, that you stopped at that point; there was some trace of faith left in your heart that prevented you from committing the greater evil. 

Secondly: 

Undoubtedly the zina for which a person is to be punished in the manner described above is penetration, where the private parts meet. As for the things that lead to zina, such as touching, kissing and putting the fingers into the vagina, although they are haraam and abhorrent, the one who does them may be punished for doing them, but he is not punished with the hadd punishment that is meted out to the zaani; rather he should be rebuked and disciplined. As for naming, sharee’ah calls these actions zina, as it says in the hadeeth narrated by al-Bukhaari (6243) and Muslim (2657) from Abu Hurayrah (may Allaah be pleased with him) from the Prophet (peace and blessings of Allaah be upon him) who said: “Allaah has decreed for the son of Adam his share of zina which will inevitably catch up with him. The zina of the eye is looking and the zina of the tongue is speaking. The heart wishes and longs and the private part confirms that or denies it.” 

According to the version narrated by Muslim: “The zina of the eyes is looking, the zina of the ears is listening, the zina of the tongue is speaking, the zina of the hand is touching, and the zina of the foot is walking. The heart wishes and longs and the private part confirms that or denies it.” 

Ibn Battaal (may Allaah have mercy on him) said: Looking and speaking are called zina because they invite one to true zina. Hence he said: “the private part confirms that or denies it.” End quote from Fath al-Baari. 

So hasten to repent to Allaah and cut off all ties with this woman who may cause you to lose your faith and chastity and make you one of the immoral evildoers. We ask Allaah to keep you safe and sound. Beware of the tricks of the Shaytaan, for the matter starts with a look and may end in evil deeds; may Allaah protect us and you. 

And Allaah knows best.