Noun

1. Civilians trained as soldiers but not part of the regular army
2. Formality and propriety of manner
3. Something kept back or saved for future use or a special purpose
4. An athlete who plays only when a starter on the team is replaced
5. (medicine) potential capacity to respond in order to maintain vital functions
6. A district that is reserved for particular purpose
7. Armed forces that are not on active duty but can be called in an emergency
8. The trait of being uncommunicative; not volunteering anything more than necessary

Verb

1. Hold back or set aside, especially for future use or contingency
2. Give or assign a resource to a particular person or cause
3. Obtain or arrange (for oneself) in advance
4. Arrange for and reserve (something for someone else) in advance