1) Able to be put to use 2) Able to put in service 3) Capable of being put to use 4) Functional 5) In working order 6) Of service 7) Operable 8) Operational 9) Ready to be put into service 10) Serviceable 11) Serving the purpose 12) Usable Found on https://www.crosswordclues.com/clue/useable