incisive - Dictionary definition and meaning for word incisive
incisive can be correlated with our incisor teeth. which is very sharp both in human and animal, and they use it to cut food thus incisive= incisor= cutting
Incisive-> It has come from Incision cutting, esp. by a surgeon. Also , Incision sounds similar to scissor (which are your four sharp teeth) used for cutting.
incisive---incisor...cisor which is used to cut something is sharp :)