細い: thin

彼女かのじょは指ゆびが細ほそい。

She has slender fingers.

形かたちは、下したが細ほそい深鉢ふかばちがよく使つかわれました。

As for shape, deep bowls that were narrow at the bottom were often used.

麻あさは、細ほそくてじょうぶな糸いとが取とれる植物しょくぶつです。

Hemp is a plant from which thin, strong thread can be taken.