The Collaborative International Dictionary of English v.0.48:
Swear \Swear\, v. i. [imp. Swore, formerly Sware; p. p.
Sworn; p. pr. & vb. n. Swearing.] [OE. swerien, AS.
swerian; akin to D. zweren, OS. swerian, OHG. swerien, G.
schw["o]ren, Icel. sverja, Sw. sv[aum]rja, Dan. svaerge,
Icel. & Sw. svara to answer, Dan. svare, Dan. & Sw. svar an
answer, Goth. swaran to swear, and perhaps to E. swarm.
[root]177. Cf. Answer.]
1. To affirm or utter a solemn declaration, with an appeal to
God for the truth of what is affirmed; to make a promise,
threat, or resolve on oath; also, to affirm solemnly by
some sacred object, or one regarded as sacred, as the
Bible, the Koran, etc.
Ye shall swear by my name falsely. --Lev. xix.
I swear by all the Roman gods. --Shak.
2. (Law) To give evidence on oath; as, to swear to the truth
of a statement; he swore against the prisoner.
3. To make an appeal to God in an irreverant manner; to use
the name of God or sacred things profanely; to call upon
God in imprecation; to curse.
[I] swore little; diced not above seven times a
To swear by, to place great confidence in a person or
thing; to trust implicitly as an authority. "I simply
meant to ask if you are one of those who swear by Lord
Verulam." --Miss Edgeworth.
To swear off, to make a solemn vow, or a serious
resolution, to abstain from something; as, to swear off