Definition of "interested"

I was even mortified at those instances of his liberality, which my situation compelled me to receive, lest, being but little acquainted with my disposition, he should suspect me of being interested in my love […] .

1751, [Tobias] Smollett, The Adventures of Peregrine Pickle […], volumes (please specify |volume=I to IV), London: Harrison and Co., […]

they impressed my youthful mind with a sincere aversion to the northern inhabitants of Britain, as a people bloodthirsty in time of war, treacherous during truce, interested, selfish, avaricious, and tricky in the business of peaceful life, and having few good qualities [...].

1817 December 31 (indicated as 1818), [Walter Scott], Rob Roy. […], volumes (please specify |volume=I to III), Edinburgh: […] James Ballantyne and Co. for Archibald Constable and Co. […]; London: Longman, Hurst, Rees, Orme, and Brown

"Oh, you are quite wrong!" cried his mother; "no love of fortune, nor of ambition, could have tempted Norbourne to desert you. Little, indeed, do you know his high and generous nature, when you suppose that he could be actuated by an interested motive."

1837, L[etitia] E[lizabeth] L[andon], “The Disclosure”, in Ethel Churchill: Or, The Two Brides. […], volume III, London: Henry Colburn, […], page 309

He maintained -- the thought is not unnatural in a royal historiographer -- that the generous actions of great princes are often twisted and misrepresented by interested critics.

1982, Peter Partner, The Murdered Magicians: The Templars and Their Myth, Oxford University Press, page 99