extension field

15 LETTERS · STARTS WITH E

extension field is a valid 15-letter word worth 25 points in Scrabble and 28 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

E1X8T1E1N1S1I1O1N1F4I1E1L1D2

1 + 8 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 4 + 1 + 1 + 1 + 2 =25 PTS

DOUBLE WORD → 50TRIPLE WORD → 75

MEANING

What does extension field mean?