ill humour

NOUN
10 LETTERS · 2 SYLLABLES · STARTS WITH I

ill humour is a valid 10-letter word worth 14 points in Scrabble and 18 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
I1L1L1H4U1M3O1U1R1
1 + 1 + 1 + 0 + 4 + 1 + 3 + 1 + 1 + 1 =14 PTS
DOUBLE WORD → 28TRIPLE WORD → 42
MEANING

What does ill humour mean?