Noah Webster
Father-in-law
F'ATHER-IN-LAW, noun The father of one's husband or wife; and a man who marries a woman who has children by a former husband is called the father in law or step-father of those children.
F'ATHER, verb transitive
1. To adopt; to take the child of another as one's own.
2. To adopt any thing as one's own; to profess to be the author.
Men of wit often father'd what he writ.
3. To ascribe or charge to one as his offspring or production; with on.
My name was made use of by several persons, one of whom was pleased to father on me a new set of productions.