Across: 2.sip, 5.thin, 6.ouch, 7.our, 8.stab, 10.tier, 13.tape, 16.feet, 18.ape, 19.char, 20.able, 21.nor

Down: 1.chat, 2.snob, 3.port, 4.acre, 8.sit, 9.asp, 11.ice, 12.rat, 14.ache, 15.earn, 16.fear, 17.eels