adverb
readily; easily; at a moment's notice
Almost always used in negative contexts (with ない, できない, etc.) to mean that something cannot be done casually or without preparation.
そんな大金はおいそれと出せない。
I can't just hand over that much money on the spot.
彼はおいそれと引き受けるような人
He's not the kind of person who would readily take on something like that.