Insipid
Part of speech: adjective
Definition: Unappetizingly flavorless. Flat; lacking character or definition. Cloyingly sweet or sentimental.
Example sentence: Taste, which enables us to distinguish all that has a flavor from that which is insipid.
Harmless
Part of speech: adjective
Definition: incapable of causing harm or dangernot intended to harm; inoffensivesafe
Example sentence: We should take astrology seriously. No, I don't mean we should believe in it. I am talking about fighting it seriously instead of humouring it as a piece of harmless fun.