Old English lifian (Anglian), libban (West Saxon) "to be, to live, have life; to experience," also "to supply oneself with food, to pass life (in some condition)," from Proto-Germanic *liben (cf. Old Norse lifa "to live, remain," Old Frisian libba, German leben, Gothic liban "to live"), from PIE root *leip- "to remain, continue" (cf. Greek liparein "to persist, persevere;" see leave). Meaning "to make a residence, dwell" is from c.1200. Related: Lived; living.
To live it up "live gaily and extravagantly" is from 1903. To live up to "act in accordance ...