You searched for: “explicative
expletive, explicative
expletive (EK spli tiv) (noun)
A word used to fill a space in a written or verbal communication that does not add meaning and is often considered crude or obscene: The editor of the newspaper did not approve of the writer's use of an expletive in his article.
explicative (EK spli kay" tiv, ik SPLIK uh tiv) (adjective)
Concerning a detailed and logical explanation: The speaker provided an explicative introduction to his topic.

The advice columnist in the local newspaper provided an explicative explanation why the use of an expletive in polite conversation is not appropriate.