half pay

from The Century Dictionary.

• noun Half the amount of wages or salary; reduced pay (seldom literally half of the full pay); a reduced allowance paid to an officer when not in actual service, or after retirement at the end of a prescribed term.
• Receiving or entitled to half-pay: as, a half-pay officer.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun reduced wage paid to someone who is not working full time