fundamental unit

16 LETTERS · STARTS WITH F

fundamental unit is a valid 16-letter word worth 21 points in Scrabble and 28 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

F4U1N1D2A1M3E1N1T1A1L1U1N1I1T1

4 + 1 + 1 + 2 + 1 + 3 + 1 + 1 + 1 + 1 + 1 + 0 + 1 + 1 + 1 + 1 =21 PTS

DOUBLE WORD → 42TRIPLE WORD → 63

MEANING

What does fundamental unit mean?