unsupportive
Not giving help, encouragement, or approval when someone needs it.
Unsupportive means failing to provide help, encouragement, or approval when someone needs it. When a friend dismisses your excitement about joining the robotics club or tells you your project idea is silly, they're being unsupportive. When parents refuse to attend your school play or show no interest in something important to you, that's unsupportive behavior.
The word describes both actions and attitudes. An unsupportive teammate might criticize your mistakes instead of helping you improve. An unsupportive environment might be a classroom where students mock each other for asking questions instead of creating a space where everyone feels safe learning.
Being unsupportive is different from offering honest feedback or constructive criticism. A supportive person might point out problems with your plan while still believing in your ability to succeed. An unsupportive person just shoots down your ideas without offering alternatives or encouragement. When someone feels unsupported, they can feel alone, discouraged, or like their efforts don't matter to anyone else.
The opposite is supportive: offering encouragement, showing up when it matters, and helping others believe in themselves even when things get difficult.