having already been used

scrawling on the back of a used envelope

second-hand

a used car

take, hold, or deploy (something) as a means of accomplishing or achieving something; employ

she used her key to open the front door

the poem uses simple language

take or consume (an amount) from a limited supply

we have used all the available funds

describing an action or situation that was done repeatedly or existed for a period in the past

this road used to be a dirt track

I used to give him lifts home

be or become familiar with (someone or something) through experience

she was used to getting what she wanted

he's weird, but you just have to get used to him

one would like or benefit from

I could use another cup of coffee