spectral luminous efficiency

28 LETTERS · STARTS WITH S

spectral luminous efficiency is a valid 28-letter word worth 45 points in Scrabble and 55 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

S1P3E1C3T1R1A1L1L1U1M3I1N1O1U1S1E1F4F4I1C3I1E1N1C3Y4

1 + 3 + 1 + 3 + 1 + 1 + 1 + 1 + 0 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 1 + 0 + 1 + 4 + 4 + 1 + 3 + 1 + 1 + 1 + 3 + 4 =45 PTS

DOUBLE WORD → 90TRIPLE WORD → 135

MEANING

What does spectral luminous efficiency mean?