"I am going to recoup one of my earlier essays on this subject --
there were so many clever things that I blurted out within it,
as the initial incitements of the topic struck me on my first
impression, that my elastic, all too elastic stores of memory
are already beginning to blur into obliviscence, that form of
resilience in impressionability that I suspect you share, too.
Besides which concern I am for the moment earnestly of a mind
and a mettle to keep on broadening out this malleable subject
to take in some aspects of what we mean by definition, in the
first place, if that is indeed the only place for definitions
to make a place for themselves, which I occasionally question."

I could not find dictionary definition, but think it is coinage from "oblivion".
oblivion
n.
5OFr < L oblivio < oblivisci, to forget < ob3 (see OB3) + (prob.) levis, smooth < IE base *lei3, slippery > LIME16
1 a forgetting or having forgotten; forgetfulness
2 the condition or fact of being forgotten
3 official overlooking of offenses; pardon