not helpful; not effective; to make use of, take advantage of, something

use

the state of being relevant

pertinence

(an act of) help or assistance to another or others; an organized system of work etc for the needs of the public

aid, help

to cause (something) to act or serve for a purpose; to have the use of a supply (until nothing is left); to behave towards (a person)

application; employment

the quality of being useful; a public service such as the supply of water or a bus service

serviceableness