(Slavic grammar) A verb of motion whose motion is multidirectional (as opposed to unidirectional) or indirect, or whose action is repeated or in a series (iterative), instead of being a single, completed action. Abstract verbs are always imperfective in aspect, even with prefixes that are normally associated with the perfective aspect.
(abstract) I went to the post office. (there and back, multidirectional)
(concrete) I went to the post office. (and am there now, unidirectional)
(abstract) I went to the theater and had an accident. (the event occurred during the trip there and back)
(concrete) I went to the theater and had an accident. (the event occurred at the theater)
(abstract) I like to fly. (repeated action) Polish example: Lubię latać. (infinitive: latać)
(concrete) I flew to Frankfurt. (a single, completed action) Polish example: Poleciałem do Frankfurtu. (infinitive: (po)lecieć)