reservebag
nounUK /rɪˈzɜːvbæɡ/
US /rɪˈzɜːrvbæɡ/
A reservebag is a special bag you keep for later in case you need it.
She packed a reservebag with snacks for the long trip.
OTHER MEANINGS
2. A bag set aside as a replacement if the main one is lost or damaged.
Keep a reservebag in the car in case your shopping bag tears.
3. A small pouch of extra supplies kept in reserve during an activity.
The hiker carried a reservebag of water and bandages.
4. In gaming, a bag where players store items they may need later.
He dropped the rare potion into his reservebag for the boss fight.