Merriam Webster has this definition for the word “ninny”.
The part that bothers me is the etymology. I’m not so sure about the contraction of “an innocent.” In fact, Merriam Webster doesn’t seem too sure about it either.
Can someone hook me up with the straight dope?
From Julian Burnside- A Bit About Words
"One of the commonest forms of corruption is aphesis: "The gradual and unintentional loss of a short unaccented vowel at the beginning of a word " [OED 2nd edn]
Cute is an aphetic form of acute; longshore is the truncated form of alongshore. This explains the American usage longshoremanfor our stevedore. Stevedore is itself an aphetic adaptation of the Spanish estivador, which drives from estivar: to stow a cargo.
Likewise, sample is an aphetic form of example; backward is an aphetic form of abackward; and vanguard was once avauntguard, from which avantguard also derives.
Ninny is an aphetic and abbreviated form of an innocent. More recently, we have squire from esquire, specially for especially. In the language of the law, several ambiguous forms survive: vowand avow; void and avoid."
ninny /'nini/ noun, colloquial, late sixteenth century. [Origin uncertain: perhaps from INN(OCENT with prefixed n-: see -Y6.] A simpleton; a fool.
Thank you much.