operation

[1]	function , functioning , working , running , performance , action , motion , movement
[2]	manipulation , handling , direction , running , control , management , managing , manoeuvring
[3]	undertaking , enterprise , venture , project , affair , deal , procedure , proceeding , (day-to-day) business , transaction
[4]	operations , action , manoeuvre , mission , task , campaign , exercise
[5]	in/into operation , military operation , functioning , operative , in effect , in force , operating , operational , functional , effective , efficacious
[6]	surgery , surgical operation , surgical procedure , surgical process
[7]	procedure
[8]	functioning , performance
[9]	process , cognitive process , mental process , cognitive operation
[10]	mathematical process , mathematical operation