1. Require (ing) a lot of work/attention to maintain.
2. Require (ing) a lot of money or attention to appearance.
3. Require (ing) a high emotional investment or en excessive amount of money.
EXAMPLES OF HIGH-MAINTENANCE BEHAVIOR:
-Having frequent professional cosmetic consultations, such as hair-dressing, manicures and pedicures
-Excessive worthless spending (tricking)
-Being too delicate or suavé
NOTE: high-maintenance is primarily used to refer to attractive straight women or a person/people that's stuck on self.