especially; particularly; above all
Used to single out something as notably more important or prominent than others. Often interchangeable with 特に, but slightly more formal or emphatic.
See also: 取り分け
This issue is especially important.
彼は取り分けて数学が得意だ。
He is particularly good at math.
Derived from the verb 取り分ける (to distribute, to set aside), with the て-form used adverbially to mean 'setting aside from the rest' → 'especially'.