Skills or knowledge that are seldom applied are likely to be lost with time. / Property and privileges will be lost if they are not utilized.

Acclimation, adjustment.

(intransitive) To become accustomed to something; to acclimate; to adjust. / (transitive) to make accustomed, to accustom, to habituate (someone to something).

plural of useful idiot

present participle of ill-use

simple past tense and past participle of ill-use

Having been treated badly.

Exclamation of surprise.

Third-person singular simple present indicative form of put to use

present participle of put to use