traveling salesman

NOUN
18 LETTERS · STARTS WITH T

traveling salesman is a valid 18-letter word worth 23 points in Scrabble and 30 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
T1R1A1V4E1L1I1N1G2S1A1L1E1S1M3A1N1
1 + 1 + 1 + 4 + 1 + 1 + 1 + 1 + 2 + 0 + 1 + 1 + 1 + 1 + 1 + 3 + 1 + 1 =23 PTS
DOUBLE WORD → 46TRIPLE WORD → 69
MEANING

What does traveling salesman mean?