I would like to know what actions would be considered zina according to Islam. Is it limited to sexual intercourse?
Anything that involves "penetration of head of male penis into female vagina (with or without ejaculation)" would constitute zina requiring Hadd punishment. This has been agreed upon by scholars (of Ahlus sunnah).
The things that lead to zina such as touching, kissing, and rubbing the private parts together without penetrating do not come under the ruling on zina that require Hadd punishment. However, such activities which may lead to zina (fornication) are haraam and abhorent.
Allah says (interpretation of meaning):
Also, in terminology of Sharee'ah, zina can be committed by eyes, ears, tongue, hand or feet due to the following Hadiths:
According to the version narrated by Muslim:
The zina of eyes or tongue or desire doesn't entail Hadd punishment but are absolutely haraam.
Reference: The zina which incurs the hadd punishment
Yes, it's limited to sexual intercourse. There are four kinds of zina:
Where each has a different retribution.
There's difference in opinion between Shi'a and Sunni, Shi'a defines zina as something more broad:
Zina زنا has little or even nothing to do with sexuality than most people think. It has a lot todo with abuse of financial contract(meethaq) between husband and wife (zawjayn).
sexuality between two couples and hence hereditary nature of the relationship is depicted in the Quran as ba3l بعل rather than zawj زوج , as in 11:72 and 4:128.
I would argue that Zina is more closer to za ya na than to za na ya. It has analgously same construct as Riba.
If Riba is the abuse of the usage of ra ya ba (uncertainties/futures/probabilities/etc) in the expense of others involved in the contract for example abuse of hedging, abuse of money printing (if we consider printing money as a means of estimating value of resources), etc. , then Zina is the abuse of the usage of za ya na (goodness/glamour/resource) in the expense of others involved in the contract for example financial embezelments, using the spouse's money irresponsibly causing severe financial losses.
Both are acts of taking something from someone without the other parties consent. And hence a kin to stealing but have different levels, the former is much severe than the latter thus the former is justifiable by an act of embargo/حرب (from the term mi7raab/secluded places) while the latter is treated with flogging.. and depending on the severity of the act, the flogging can be done as minimal as the example of ayoub AS to his wife in 38:44