Definition of: subjunctive

(səb·jungk′tiv) Gram. adjective
Of or pertaining to that mood of the finite verb that is used to express a future contingency, a supposition implying the contrary, a mere supposition with indefinite time, or a wish or desire. In English the forms of the subjunctive mood are introduced by conjunctions of condition, doubt, contingency, possibility, etc., as if, though, lest, unless, that, till, or whether, but verbs in conditional clauses are not always in the subjunctive mood, for the use of these conjunctions with the indicative is very common.
—noun
1. The subjunctive mood.
2. A verb form or construction in this mood. [<L subjunctivus <subjunctus, pp. of subjungere SUBJOIN]