simple extension

16 LETTERS · STARTS WITH S

simple extension is a valid 16-letter word worth 26 points in Scrabble and 31 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

S1I1M3P3L1E1E1X8T1E1N1S1I1O1N1

1 + 1 + 3 + 3 + 1 + 1 + 0 + 1 + 8 + 1 + 1 + 1 + 1 + 1 + 1 + 1 =26 PTS

DOUBLE WORD → 52TRIPLE WORD → 78

MEANING

What does simple extension mean?