“Ad hoc” is a phrase originating from Latin and literally meaning “to this”, or “for this”. In English, it is used to say “for this purpose” or “precisely for this” to define a particular way of resolving a specific problem or an issue, without the intention to further adjust this solution to other use cases.
“Ad hoc” can also be used as an adjective standing for momentary, conditional and spontaneous solutions to a particular difficulty that is not intended to be used as a model of dealing with similar challenges. In other words, “ad hoc” can be meant as “individual”.
For instance, an “ad hoc” ruling can be made on a legal case if a judge wants to review the particulars or specific case-related circumstances, provided the ruling won’t be used as a prototype in studying similar cases.
In IT, “ad hoc” is applicable when speaking of an “ad hoc solution” meaning an immediate, unique solution designed for a particular product or problem to satisfy customer needs.