From Wiktionary, the free dictionary
From agreeing + -ness.
agreeingness (uncountable)
- (rare, colloquial, possibly nonstandard) The state or quality of agreeing.
1998 December 18, northern lad, “Re: ARGH”, in alt.kids-talk[1] (Usenet):pure agreeingness* that was scarily poetic.
1999 October 5, Joxer, “Re: Important message to prospective DR WHO producers”, in rec.arts.drwho[2] (Usenet):(snip lots of lovely fluffy agreeingness)
2005 January 16, DC, “Re: It's only words...”, in talk.religion.buddhism[3] (Usenet):Such harmony and agreeingness!