verb (used without object), swore or (Archaic) sware; sworn; swear·ing.
verb (used with object), swore or (Archaic) sware; sworn; swear·ing.
- to name (a sacred being or thing) as one's witness or guarantee in swearing.
- Informal.to have great confidence in; rely on: He swears by his dentist.
- to have certain knowledge of: I thought I saw him leaving, but I couldn't swear by it.
Origin of swear
Synonyms for swear
verb swears, swearing, swore or sworn
- to invoke (a deity, etc) by name as a witness or guarantee to an oath
- to trust implicitly; have complete confidence (in)
Word Origin for swear
Old English swerian "take an oath" (class VI strong verb; past tense swor, past participle sworen), from Proto-Germanic *swarjan-, (cf. Old Saxon swerian, Old Norse sverja, Danish sverge, Old Frisian swera, Middle Dutch swaren, Old High German swerien, German schwören, Gothic swaren "to swear"), from PIE root *swer- (1) "to speak, talk, say" (cf. Old Church Slavonic svara "quarrel"). Also related to the second element in answer. The secondary sense of "use bad language" (early 15c.) developed from the notion of "invoke sacred names." Swear-word is American English colloquial from 1883. Swear off "desist as with a vow" is from 1898.
Have great reliance on or confidence in, as in She swears by her personal physician. [Early 1800s]
Also, swear to. Have reliable knowledge of, be sure of, as in I think she was going to the library but I can't swear to it. [Mid-1700s]
Take an oath by, as in I swear by all the saints in heaven. [Early 1200s]