Slim, slender — a mimetic word describing something thin and graceful (e.g., a slim figure or delicate fingers).
彼女はほっそりした体型で、ドレスがよく似合う。
She has a slim figure and looks great in dresses.
ほっそりとした指先でピアノを弾く姿が印象的だった。
Her playing with slender fingers was impressive.
冬でも彼はほっそり見えるが、健康的だ。
Even in winter he looks slim, but healthy.