Alright then pardner, get out yer dictionary, and let's have a look...

My dictionary...

Main Entry: 1in-vec-tive
Pronunciation: in-'vek-tiv
Function: adjective
Etymology: Middle English invectif, from Middle French, from Latin invectivus, from invectus, past participle of invehere
: of, relating to, or characterized by insult or abuse