isothermal line

15 LETTERS · STARTS WITH I

isothermal line is a valid 15-letter word worth 19 points in Scrabble and 22 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

I1S1O1T1H4E1R1M3A1L1L1I1N1E1

1 + 1 + 1 + 1 + 4 + 1 + 1 + 3 + 1 + 1 + 0 + 1 + 1 + 1 + 1 =19 PTS

DOUBLE WORD → 38TRIPLE WORD → 57

MEANING

What does isothermal line mean?