reuse

user; consumer / employer

employee / servant

something that has gone unused

passive, inactive, timid

(gambling, idiomatic) Snake eyes: two ones, after rolling two dice. / (derogatory, idiomatic) Wearing two layers of hitoemono (unlined summer-weight kimono).

hairpin

hairpin / (computing) pinning (attaching a UI item to another item)

(computing) to pin (attach a UI item to another item)

bobby pin (hairpin)