insecure

As a noun concern

is that which affects one's welfare or happiness.

As a verb concern

is to relate or belong to; to have reference to or connection with; to affect the interest of; to be of importance to.

As an adjective insecure is

not secure.

As adjectives the difference between emotional and insecure

is that emotional is of or relating to the emotions while insecure is not secure.

As adjectives the difference between vulnerable and insecure

is that vulnerable is more or most likely to be exposed to the chance of being attacked or harmed, either physically or emotionally while insecure is not secure.

As a noun taxonomy

is the science or the technique used to make a classification.

As an adjective insecure is

not secure.

As adjectives the difference between insecure and anxious

is that insecure is not secure while anxious is full of anxiety or disquietude; greatly concerned or solicitous, especially respecting something future or unknown; being in painful suspense;—applied to persons; as, anxious for the issue of a battle.

As adjectives the difference between insecure and unsiker

is that insecure is not secure while unsiker is (obsolete) unsafe, insecure.

As adjectives the difference between insecure and hackable

is that insecure is not secure while hackable is (computing) that can be hacked or broken into; insecure, vulnerable.