3 letters:
pic, pik, pix

4 letters:
pick, pyka

5 letters:
pecor, pekar, picco, picht, picks, picky, piker, poker, vicar

6 letters:
bicker, dicker, ficker, kicker, licker, liquor, packer, picchi, picher, picked, pillar, piller, pinker, pinner, pipher, pucker, pysher, ricker, sicker, ticker, vicker, wicker, zycher

7 letters:
knicker, pickers, pickert, pickier, picture, pitcher, thicker, whicker

8 letters:
schicker