(n.) King of the castle. Ruler of the roost... until his wife comes home from work. This is one of the lowest titles a man can have, often said to be lower than unemployed. This is the masculine form of the word housewife.
-Do you think Lucas will ever have a job?
-No, but I think he would be a good househusband anyway.
A term that shouldn't even exist due to thousands of years of sociobiological and anthropological evidence in gender role. However, this word is a testament to the awful power of political correctness, which forces gender relativeness in all words. (Since housewife is a gender specific term applying to females, there should also be a polar term describing males, thus househusband)
Examples of other terms invented by political correctness: policewoman, firewoman, servicewoman...