General need:
* Destitute: Implying extreme poverty or lack of basic necessities.
* Indigent: Similar to "destitute," but emphasizing lack of resources and financial means.
* Impoverished: Focused on the state of being poor.
* Wanting: More general, meaning lacking something desirable.
Emotional need:
* Dependent: Reliant on others for support.
* Vulnerable: Easily hurt or taken advantage of.
* Clingy: Overly attached and demanding of attention.
* Insecure: Lacking self-confidence and feeling inadequate.
* Pleading: Begging for help or attention.
Specific needs:
* Hungry: Lacking food.
* Thirsty: Lacking water.
* Homeless: Lacking a place to live.
* Sick: In need of medical care.
Informal:
* In a bind: In a difficult situation.
* Down on their luck: Experiencing misfortune.
* Hard up: Lacking money or resources.
The best synonym for "needy" will depend on the specific situation and the desired level of formality.