nice-nellyism

or nice-Nel·ly·ism

[ nahys-nel-ee-iz-uh m ]
/ ˈnaɪsˈnɛl iˌɪz əm /

noun

excessive modesty; prudishness.
a euphemism: an evasive style of writing, full of circumlocutions and nice-nellyisms.

Origin of nice-nellyism

First recorded in 1935–40; nice nelly + -ism