swear upon
English
Alternative forms
- swear on
Verb
swear upon
- (transitive, formal) To take an oath on someone or something.
- to swear on the Holy Writ to speak the truth
- c. 1610-11, William Shakespeare, The Tempest, Act II, Scene ii:
- I'll swear upon that bottle to be thy true subject, for the liquor is not earthly.