expression, ichidan verb
anesthetize; put under anesthesia
Used in medical contexts for administering anesthesia to a patient or animal.
手術の前に患者に麻酔をかける。
The patient is anesthetized before the surgery.
The noun 'anesthesia'; 麻酔をかける is the verb phrase meaning 'to anesthetize'.
Compound of 麻酔 (masui, 'anesthesia') + を (o, object marker) + かける (kakeru, 'to apply'). The verb かける here carries the sense of applying or administering something.