something having a minor flaw / (grammar) a tense of verbs used in describing a past action that is incomplete or continuous

(transitive) to make imperfect

not perfect / (botany) unisexual: having either male (with stamens) or female (with pistil) flowers, but not with both. / (taxonomy) known or expected to be polyphyletic, as of a form taxon.

(uncountable) Those qualities or features that are imperfect; the characteristic, state, or quality of being imperfect.

Of, relating to or having the properties of the imperfective aspect.

The imperfective aspect; a verb having this aspect.

plural of imperfection

(grammar) The state or quality of being imperfective

In a way that cannot be perfected.

Incapable of being made perfect.