adverb
slightly open; narrowly; finely; thinly
Describes doing something in a slight, narrow, or fine manner. Often used with verbs like 開ける (open a little), 切る (cut finely), or 目を開ける (open one's eyes narrowly).
窓を細めに開けて、風を入れた。
I opened the window slightly and let the breeze in.
ネギを細めに切ってください。
Please cut the green onion finely.
細い is an adjective meaning 'thin' or 'slender', while 細めに is an adverb describing the manner of doing something in a thin or slight way.
細かく means 'finely' or 'in detail', often used for cutting into small pieces or describing something minutely. 細めに emphasizes a slight or narrow degree rather than smallness.
Derived from the adjective 細い (thin) with the suffix め (indicating a slight degree) and the adverbial particle に.