Procrastinate

Definition
(minimalist theory) principle which favors covert syntax over overt syntax, if there is a choice. The underlying idea is that movement after Spell-out is 'less costly', because covert movement does not have to pied-pipe phonological features (these have already been stripped away by Spell-Out). Movement can only be procrastinated until after Spell-Out when weak features are involved; strong features are supposed to be uninterpretable at PF, and therefore they must be deleted before Spell-Out. See look-ahead.

Links
Utrecht Lexicon of Linguistics