Etymology From Middle English selfly, from Old English selflīċ (“automatic, spontaneous, voluntary”); equivalent to self + -ly.
1
Of or pertaining to self or one's own self, personal.
This denotes and declares the divided tongues, where every property had brought itself forth out of the universal sensual tongue into a selfishness and a peculiar selfly understanding, so that they did not any longer understand one another […]2001, Jed Rasula, Steve McCaffery, Imagining Language: An Anthology:
selfly
adv
Etymology From Middle English selfly, from Old English selflīċ (“automatic, spontaneous, voluntary”); equivalent to self + -ly.
1
In, of, or by one's self; of one's own accord, voluntary, automatic.
Thy gloomy Front, that selfly hath no light1880, Josuah Sylvester, The complete works of Joshuah Sylvester: