(noun): someone who is incapable of doing what he really wants because of constraints he has imposed on himself through poor life decisions
also applies to someone who strives for or achieves superficial success
Benny is 35 years old, married, and has young children. He works at an insurance company and his income matches his expenses. His family obligations prevent him from pursuing his goal of starting a company. He does not enjoy his work but is no longer young enough to switch industries. Benny is a lifefish.