1/2 NLHE live game
Hero AdKh (SB)
5 limp including Villain (BTN)
Hero raises to 17$
folds to Villain who calls (100BB deep i cover)

Flop : 7d 2h 9d
Hero bets 25$ , Villain calls

Turn 4h
Hero cheks Villain cheks

River 4c
Hero bets 75$ Villain raises to 175$
Hero ?

Villain is semifish with a respect to me , capable of doing some moves without any idea why and how. The reason i post the hand is i dont really see what hand can raise me on the river , as played he doesn`t have any sets , all draws missed ...
any toughts ?