Synonyms of the word

incapable

• adj. Not capable (of doing something); unable.
• adj. Not in a state to receive; not receptive; not susceptible; not able to admit.
• n. (dated) One who is morally or mentally weak or inefficient; an imbecile; a simpleton.

inadequate

• adj. Not adequate; unequal to the purpose; insufficient; deficient.
• n. An individual who is inadequate.

incompetent

• adj. Unskilled, lacking normally expected degree of ability.
• adj. Unable to make rational decisions, insane or otherwise cognitively impaired.
• adj. (medicine) an incompetent cervix is one that opens too early in pregnancy, provoking the baby to be born.
• n. A person who is incompetent.

insusceptible

• adj. Not susceptible.

unable

• adj. Not able; lacking a certain ability.

unqualified

• adj. Not qualified, ineligible, unfit for a position or task.
• adj. Not elaborated upon, undescribed.

unsusceptible

• adj. Not susceptible.