sustainer

transitive verb

1. to keep in existence; keep up; maintain or prolong: to sustain a mood
2. to provide for the support of; specif., to provide sustenance or nourishment for
3. to support from or as from below; carry the weight or burden of
4. to strengthen the spirits, courage, etc. of; comfort; buoy up; encourage
5. to bear up against; endure; withstand
6. to undergo or suffer (an injury, loss, etc.)
7. to uphold the validity or justice of: to sustain a verdict
8. to confirm; corroborate