O.E. bidan "to stay, continue, live, remain," also "to trust, rely" (cognate of O.N. biða, O.Fris. bidia, Goth. beidan "to wait"), apparently from PIE *bheidh-, an extended stem of one root of O.E. biddan (see
bid), the original sense of which was "to command," and "to trust"
(cf. Gk. peithein "to persuade," pistis "faith;" L. fidere "to trust," foedus "compact, treaty," O.C.S. beda "need"). Perhaps the sense evolved in prehistoric times through "endure," and "endure a wait," to "to wait." Preserved in Scotland and northern England, replaced elsewhere by abide in all senses except to bide one's time.