Longman Dictionary of Contemporary English
The Collaborative International Dictionary
Father-in-law \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.
Douglas Harper's Etymology Dictionary
Wiktionary
n. 1 One's spouse's father. 2 (context dated English) A stepfather.
WordNet
n. the father of your spouse
[also: fathers-in-law (pl)]
Usage examples of "father-in-law".
In spite of what Frederick West may or may not have told his father-in-law about his dislike for the abuse of his daughter Anna-Marie, there is no doubt that both he and his wife independently sexually abused the twelve-year-old.
When the wrath of his father-in-law had been appeased, Baldwin, now responsible for the defence of Flanders, came to Bruges with his wife, and there established his Court.
I welcomed the young man and told him that I would first take him to Madame Audibert, and that we could then go together to his father-in-law in prospective.
I had been guilty of the folly now known to you because my father-in-law intended to bury me in a convent, and that did not suit my taste.
Camille was enamoured of the Count of Melfort, the favourite of the Duchess of Chartres, who had just become Duchess of Orleans by the death of her father-in-law.
In a few days after, he espoused the Princess Catharine: he carried his father-in-law to Paris, and put himself in possession of that capital: he obtained from the parliament and the three estates a ratification of the treaty of Troye: he supported the duke of Burgundy in procuring a sentence against the murderers of his father: and he immediately turned his arms with success against the adherents of the dauphin, who, as soon as he heard of the treaty of Troye, took on him the style and authority of regent, and appealed to God and his sword for the maintenance of his title.
She concluded by telling me that if she had fallen it was the fault of her husband and of her father-in-law, both of whom she characterized as monsters rather than men.
Morgan Brock has just arrived in Hong Kong and is flaunting his knighthood that he only acquired by persuading his heirless father-in-law to adopt him who then, conveniently and almost at once thereafter, died.
His father-in-law, who owned the Ilium School of Optometry, who had set Billy up in practice, was a genius in his field.
Swiss-German Louis Wicht now managed the hotel instead of his late father-in-law Luigi Fantini.
Signor Filippo Barbone became fully satisfied that his father-in-law was not to be turned from his resolution: when it became apparent that the mother was not to be influenced, he came to the conclusion that he had made a bad bargain, and resolved to escape as soon as possible from the consequences of it.
Really, if the house had not belonged to the father-in-law of the procureur, one might have thought it some accursed place where a horrible crime had been committed.
Matters were involved in greater peril at home: for besides Sextius and Licinius, the proposers of the laws, re-elected tribunes of the commons now for the eighth time, Fabius also, military tribune, father-in-law of Stolo, avowed himself the unhesitating supporter of those laws of which he had been the adviser.
A cold shadow fell over him, and he squinted up to see the silhouette of his father-in-law, stooping to grab the handle of the bucket.
It occurred to him that Qusay and his father-in-law might be considering such a fate for him since he was the ultimate authority to whom the Amn Al-Khass teams reported.