What is a synonym for ninny?

Here are some synonyms for "ninny", depending on the specific nuance you want to convey:

Informal:

* Fool

* Simpleton

* Dolt

* Dunce

* Nitwit

* Moron (can be offensive)

* Blockhead

* Goof

* Doofus

* Chump

* Dimwit

* Buffoon (implies clumsiness)

More formal:

* Idiot

* Imbecile (archaic)

* Naive

* Gullible

* Credulous

Figurative:

* Airhead

* Clueless

* Space cadet

The best synonym for "ninny" will depend on the context and the level of formality you desire.