Sleep during winter:
— Bears must eat a lot of food before they hibernate in their caves.

synonym: hole up.

Roget 683: be inactive etc. adj.; do nothing etc. 681; move slowly etc. 275; let the grass grow under one's feet; take one's time, dawdle, drawl, droil^†, lag, hang back, slouch; loll, lollop^†; lounge, poke, loaf, loiter; go to sleep over; sleep at one's post, ne battre que d'une aile [Fr.].    take it easy, take things as they come; lead an easy life, vegetate, swim with the stream, eat the bread of idleness; loll in the lap of luxury, loll in the lap of indolence; waste time, consume time, kill time, lose time; burn daylight, waste the precious hours.    idle away time, trifle away time, fritter away time, fool away time; spend time in, take time in; peddle, piddle; potter, pudder^†, dabble, faddle fribble^†, fiddle-faddle; dally, dilly-dally.    sleep, slumber, be asleep; hibernate; oversleep; sleep like a top, sleep like a log, sleep like a dormouse; sleep soundly, heavily; doze, drowze^†, snooze, nap; take a nap etc. n.; dream; snore one's best; settle to sleep, go to sleep, go off to sleep; doze off, drop off; fall asleep; drop asleep; close the eyes, seal up the eyes, seal up eyelids; weigh down the eyelids; get sleep, nod, yawn; go to bed, turn; get some z's, stack z's [Coll.].    languish, expend itself, flag, hang fire; relax.    render idle etc. adj.; sluggardize^†; mitigate etc. 174.    ... show more

Dutch: een winterslaap houden, overwinteren

Be in an inactive or dormant state.