1. fun and entertainment, especially good conversation and company (often preceded by the): Come for the beer, lads, and stay for the craic!
2. mischievous fun; laughs: We did it just for the craic.
"How is it that hardly any major religion has looked at science and concluded, 'This is better than we thought! The Universe is much bigger than our prophets said, grander, more subtle, more elegant. God must be even greater than we dreamed'? Instead they say, 'No, no, no! My god is a little god, and I want him to stay that way.'" - Carl Sagan
"To doubt everything or to believe everything are two equally convenient solutions; both dispense with the necessity of reflection." - Henri Poincaré