[oath] n, pl oaths [ME ooth, fr. OE ath; akin to OHG eid oath, MIr oeth] (bef. 12c) 1 a (1): a solemn usu. formal calling upon God or a god to witness to the truth of what one says or to witness that one sincerely intends to do what one says (2): a solemn attestation of the truth or inviolability of one's words b: something (as a promise) corroborated by an oath
2: an irreverent or careless use of a sacred name; broadly: swearword