How Well Do You Know English Slang?
1670s, "having the form of a tube or pipe," from Latin tubulus "a small pipe" (see tube) + -ar. Teen slang sense attested by 1982, Valspeak, apparently from surfers' slang for a hollow, curling wave, ideal for riding.
Wonderful; excellent; awesome, great
[1970s+ Teenagers; fr surfing term describing a wave with a tube, that is, a cylindrical space around which the crest is curling as the wave breaks, and inside which the surfer happily rides]