15 possible answers to
Answers with 3 characters: IRK VEX Answers with 4 characters: GALL MIFF RILE Answers with 5 characters: ANNOY CHAFE GRATE PEEVE Answers with 6 characters: ABRADE NETTLE RANKLE Answers with 8 characters: IRRITATE Answers with 10 characters: ANTAGONIZE Answers with 15 characters: AGAINSTTHEGRAIN