A name of the American descent commonly used to refer to a person who has an unusually large penis. Also, Thomas is always willing to do something stupid for some laughs and while he may be butt-ass-naked running down a dock, he is still the life of the party.
Person 1: "Man, Thomas was crackin' my ass up last night!"
Person 2: "I know man, me too. I can't believe he really did that (and didn't even get paid)."