noun

1. the act of reserving or that which is reserved; specif.,
   1. a withholding of a right, interest, etc.
   2. that part of a deed or contract which provides for this
   3. ☆ public land set aside for some special use an Indian reservation, military reservation
   4. ☆ an arrangement by which a hotel room, theater or airline ticket, etc. is set aside and held until called for
   5. ☆ anything so reserved in advance
   6. ☆ the promise of or a request for such an arrangement
2. a limiting condition or qualification, tacit or expressed, as in an agreement to make a promise with mental reservations

Etymology: ME < ML reservatio