7 letters · 9 points in Scrabble
adjective constituting a tube; having hollow tubes (as for the passage of fluids)
originFrom Latin tubulus + -ar. By surface analysis, tubule + -ar. The sense meaning "cool" or "awesome" is believed to be a figurative extension originating in surfing lingo, from the way that an excellent wave encloses a surfer within tubular walls of water.
Etymology from Wiktionary, CC BY-SA 3.0