Weak and affectedly sentimental.
Namby-Pamby was the disparaging nickname given to the English poet and playwright, Ambrose Phillips (1674 - 1749). His contemporaries Henry Carey, John Gay, Alexander Pope and Jonathan Swift all used the term to describe both him and his works. Carey was the first to put it into print, in a reaction against the style of Philips's poem 'To the Honourable Miss Carteret' (1725), when he published the poem Namby-Pamby (1726):
All ye poets of the age,
All ye witlings of the stage …
Namby-Pamby is your guide,
Albion's joy, Hibernia's pride.
Rhimy-pim'd on Missy Miss
From the navel to the knee;
That her father's gracy grace
Might give him a placy place.
This mimicked the rather cloying sentimental reduplication of some poems that Phillips had written for the children of aristocratic acquaintances. Pope subsequently made similar fun of Phillips in his poem The Dunciad - "Beneath his reign, shall ... Namby Pamby be prefer'd for Wit!"
The term began to be used to describe a style of ineffectual writing soon afterwards. For example, William Ayre, in his Memoirs of the life and writings of Alexander Pope (1745), writes:
"He us'd to write Verses on Infants, in a strange Stile, which Dean Swift calls the Namby Pamby Stile."
Soon afterwards again it was used in an extended manner to refer to anything weak or ineffectual. For example, The Westmoreland Magazine, 1774, refers to "A namby-pamby Duke".