pigheadedness

NOUN
13 LETTERS · STARTS WITH P

pigheadedness is a valid 13-letter word worth 21 points in Scrabble and 23 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
P3I1G2H4E1A1D2E1D2N1E1S1S1
3 + 1 + 2 + 4 + 1 + 1 + 2 + 1 + 2 + 1 + 1 + 1 + 1 =21 PTS
DOUBLE WORD → 42TRIPLE WORD → 63
MEANING

What does pigheadedness mean?