fit or ready for use or service;
"the toaster was still functional even after being dropped"
"the lawnmower is a bit rusty but still usable"
"an operational aircraft"
"the dishwasher is now in working order"
capable of being put to use;
convenient for use or disposal;
"the house is available after July 1"
"2000 square feet of usable office space"
- They convert units of heat into useable engineering units that serve as input signals for process controllers and recorders.