What does "six four" mean in the text below?
Here's an extract from the catcher in the rye;
He was a very peculiar guy. He was a
senior, and he'd been at Pencey the whole four years and all, but nobody
ever called him anything except "Ackley." Not even Herb Gale, his own
roommate, ever called him "Bob" or even "Ack." If he ever gets married, his
own wife'll probably call him "Ackley." He was one of these very, very tall,
round-shouldered guys--he was about six four--with lousy teeth. The whole
time he roomed next to me, I never even once saw him brush his teeth.