tubule

NOUN /tubjul/
6 LETTERS · 2 SYLLABLES · STARTS WITH T

tubule is a valid 6-letter word worth 8 points in Scrabble and 12 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
T1U1B3U1L1E1
1 + 1 + 3 + 1 + 1 + 1 =8 PTS
DOUBLE WORD → 16TRIPLE WORD → 24
MEANING

What does tubule mean?