Yes, hock is a Scrabble word!
...and is worth 13 points in Scrabble, and 13 points in Words with Friends
hock
Verb
1. Leave as a guarantee in return for money
2. Disable by cutting the hock
Noun
1. Any of several white wines from the Rhine River valley in Germany (`hock' is British usage)
2. Tarsal joint of the hind leg of hoofed mammals; corresponds to the human ankle
What Scrabble words can I make with the letters in hock?
2 Letter Words