Definitions for: Father-in-law

[n] the father of your spouse

Webster (1913) Definition: Fa"ther-in-law`, n.; pl. Fathers-in-law.
The father of one's husband or wife; -- correlative to
son-in-law and daughter-in-law.

Note: A man who marries a woman having children already, is
sometimes, though erroneously, called their
father-in-law.

See Also: begetter, father, in-law, male parent, relative-in-law