HE ФУНТ ИЗЮМУ (-a) coll, often humorNPthese forms onlysubj-compl with бытыз ( subj: usu.abstr) , usu. presfixedWO
sth. is no trifle, is a serious matter, is not to be taken lightly
X не фунт изюму - X is nothing to sneeze (laugh) at
X is no joke.
Сколько видел Федор за свою короткую жизнь, сколько слышал, войны хлебнул четыре ровных годика, тоже не фунт изюма... (Максимов 1). Fyodor had seen and heard a good deal in his short life. He'd supped four full years of war, which is also no joke (1a).