1.Tending or conducing to make perfect, or to bring to perfection; usually followed by of. "A perfective alteration." "Actions perfective of their natures."
2.(Gram.) Denoting an aspect of verbs which indicates completion of an action, and is sometimes explicitly marked in verbal inflection, as in the Russian language; as, the perfective form of a verb. The use of a perfective form rather than the simple past indicates reference to a completed event, rather than to a process that took place in the past.
...
