An Etymological Dictionary of Astronomy and Astrophysics

To continue in time; go on; endure.

Etymology (EN): M.E. lasten, from O.E. læstan “to continue, endure;” cf. Goth. laistjan “to follow after,” Ger. leisten “to perform, achieve,”), from PIE root *lois- “furrow, track.”

Etymology (PE): Pâyidan “to watch, observe; remain or continue in existence, last,” variants pâsidan, pâhidan; Mid.Pers. pây- “to protect, guard;” Sogdian p’y “to observe, protect, watch over;” O.Pers. pā- “to protect,” pāta- “protected;” Av. pā- “to protect,” pāti “guards,” nipā(y)- (with ni-) “to watch, observe, guard,” nipātar- “protector, watcher,” nipāθri- “protectress;”
cf. Skt. pā- “to protect, keep,” tanû.pā- “protecting the body,” paś.pā- “shepherd;” Gk. poma “lid, cover,” poimen “shepherd;” L. pascere “to put out to graze,” pastor “shepherd;” Lith. piemuo “shepherd;” PIE base *pā- “to protect, feed.”