ADJECTIVE (2)

1. capable of being used up;

2. capable of being used up; capable of being exhausted;
- Example: "our exhaustible reserves of fossil fuel"

The Collaborative International Dictionary of English v.0.48:

Exhaustible \Ex*haust"i*ble\, a.
   Capable of being exhausted, drained off, or expended.
   Opposite of inexhaustible. --Johnson.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

exhaustible
    adj 1: capable of being used up [ant: inexhaustible]
    2: capable of being used up; capable of being exhausted; "our
       exhaustible reserves of fossil fuel"