to cap
Preserved but no longer current.
Meaning · English
To take one's oath. I will cap downright; I will swear home. CANT.
Era: ca. 1811 (Georgian)
Where it’s used:
Origin
British & Irish English
Sources & notes
Historical definition reproduced from Grose’s Dictionary of the Vulgar Tongue (1811 edition, public domain; Project Gutenberg #5402, retrieved 2026-07-31). Reflects the attitudes of its era.
Common questions
What does “to cap” mean?
To take one's oath. I will cap downright; I will swear home. CANT.
Is “to cap” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.