noun, noun or participle which takes 'suru'
telephone order; ordering by phone
Refers to placing an order via telephone call. Can be used as a noun or with する to mean 'to order by phone'.
電話注文は24時間受け付けています。
We accept telephone orders 24 hours a day.
ピザを電話注文した。
I ordered pizza by phone.
ネット注文 means 'online order', while 電話注文 specifically refers to ordering by telephone.
Compound of 電話 (telephone) and 注文 (order).