1) Bile 2) Bitchiness 3) Cattiness 4) Cruelty 5) Filthiness 6) Foulness 7) Hatred 8) Malice 9) Meanness 10) Rudeness 11) Spite 12) Unkindness 13) Unpleasantness 14) Venom 1) Callousness 2) Conflict 3) Cruelty 4) Filth 5) Filthiness 6) Foulness 7) Harshness 8) Heartlessness 9) Ill temper 10) Immorality 11) Mean behavior 12) Mean quality 13) Meanness 14) Nasty goings-on 15) Offensiveness 16) Ruthlessness 17) Spitefulness 18) Ugliness 19) Unpleasantness 20) Unpleasantness, spite 
• (n.) The quality or state of being nasty; extreme filthness; dirtiness; also, indecency; obscenity. • (n.) The quality or state of being nasty; extreme filthness; dirtiness; also, indecency; obscenity.
Nas'ti·ness noun The quality or state of being nasty; extreme filthness; dirtiness; also, indecency; obscenity. « The nastiness of Plautus and Aristophanes.» Dryden. 
[n] - the quality of being unpleasant
noun the quality of being unpleasant; `I flinched at the nastiness of his wound`