perfective

1. Tending toward perfection.
2. Grammar. Of, related to, or being the aspect that expresses the completion or the result of the action denoted by the verb.

1. The perfective aspect.
2. A perfective verb form.
3. A verb having a perfective form.

The noun has 2 meanings:

Meaning #1: a tense of verbs used in describing action that has been completed (sometimes regarded as perfective aspect)
  Synonyms: perfective tense, perfect, perfect tense

Meaning #2: the aspect of a verb that expresses a completed completed action
  Synonym: perfective aspect