More recently than the other answers Pope Francis gave an address to the Pontifical Academy of Sciences on 27 October 2014
... When we read the account of Creation in Genesis we risk imagining that God was a magician, complete with an all powerful magic wand. But that was not so. He created beings and he let them develop according to the internal laws ...
Celibate = unmarried (cælebs = single, unmarried)
The Church has allowed married men to become priests. St. Peter, for example, was married.
Continent = not having sexual relations
The Church has
always required all (married or celibate) clerics to be 100% continent and
never allowed priests to marry after their ordinations.