lymphoid tissue

NOUN
15 LETTERS · STARTS WITH L

lymphoid tissue is a valid 15-letter word worth 25 points in Scrabble and 27 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
L1Y4M3P3H4O1I1D2T1I1S1S1U1E1
1 + 4 + 3 + 3 + 4 + 1 + 1 + 2 + 0 + 1 + 1 + 1 + 1 + 1 + 1 =25 PTS
DOUBLE WORD → 50TRIPLE WORD → 75
MEANING

What does lymphoid tissue mean?