moving staircase

NOUN /muvɪŋ_'stɜr,keɪs/
16 LETTERS · 3 SYLLABLES · STARTS WITH M

moving staircase is a valid 16-letter word worth 23 points in Scrabble and 28 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
M3O1V4I1N1G2S1T1A1I1R1C3A1S1E1
3 + 1 + 4 + 1 + 1 + 2 + 0 + 1 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 =23 PTS
DOUBLE WORD → 46TRIPLE WORD → 69
MEANING

What does moving staircase mean?

NOUN · 1 SENSE
1

A stairway whose steps move continuously on a circulating belt.