A wrongdoer; malefactor.

plural of ill-doer

poorly fitted / improperly matched; unsuitable

(numerical analysis) Having a high condition number. / Having a poor condition.

Poorly considered.

not well suited to each other; poorly matched.

having an unhealthy appearance / unattractive; ugly / of evil or sinister appearance

present participle of ill-use

simple past tense and past participle of ill-use

Having been treated badly.