noun
penlight
A small, pen-shaped flashlight, often used in medical examinations or as a concert light.
医者がペンライトで患者の瞳孔を調べた。
The doctor examined the patient's pupils with a penlight.
コンサートでペンライトを振る。
Wave a penlight at a concert.
懐中電灯 is a general flashlight, while ペンライト specifically refers to a small, pen-shaped light.
Loanword from English 'penlight'.