door guard

NOUN
10 LETTERS · STARTS WITH D

door guard is a valid 10-letter word worth 12 points in Scrabble and 14 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
D2O1O1R1G2U1A1R1D2
2 + 1 + 1 + 1 + 0 + 2 + 1 + 1 + 1 + 2 =12 PTS
DOUBLE WORD → 24TRIPLE WORD → 36
MEANING

What does door guard mean?