UNFIT
unfit
(adjective) not in good physical or mental condition; out of condition; “fat and very unfit”; “certified as unfit for army service”; “drunk and unfit for service”
unfit
(adjective) below the required standards for a purpose; “an unfit parent”; “unfit for human consumption”
bad, unfit, unsound
(adjective) physically unsound or diseased; “has a bad back”; “a bad heart”; “bad teeth”; “an unsound limb”; “unsound teeth”
disqualify, unfit, indispose
(verb) make unfit or unsuitable; “Your income disqualifies you”
Source: WordNet® 3.1
Etymology
Adjective
unfit (comparative unfitter, )
Not fit; not having the correct requirements.
Not fit, not having a good physical demeanor.
Verb
unfit (third-person singular simple present unfits, present participle unfitting, simple past and past participle unfitted)
To make unfit; to render unsuitable, spoil, disqualify.
Source: Wiktionary
Un*fit", v. t. Etym: [1st pref. un- + fit.]
Definition: To make unsuitable or incompetent; to deprive of the strength,
skill, or proper qualities for anything; to disable; to incapacitate;
to disqualify; as, sickness unfits a man for labor; sin unfits us for
the society of holy beings.
Un*fit", a. Etym: [Pref. un- + fit.]
Definition: Not fit; unsuitable.
– Un*fit"ly, adv.
– Un*fit"ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition