Wiktionary
n. (context grammar English): The '''imperfective aspect''' is a feature of the verb which denotes an action or condition that does not have a fixed temporal boundary, but is habitual, unfinished, continuous, repetitive or in progress.
WordNet
n. aspect without regard to the beginning or completion of the action of the verb [syn: imperfective]
Wikipedia
The imperfective ( abbreviated or more ambiguously ) is a grammatical aspect used to describe a situation viewed with interior composition. The imperfective is used in language to describe ongoing, habitual, repeated, or similar semantic roles, whether that situation occurs in the past, present, or future. Although many languages have a general imperfective, others have distinct aspects for one or more of its various roles, such as progressive, habitual, and iterative aspects.