n. [ L. ] 1. One who, or that which, operates or produces an effect. [ 1913 Webster ]
2. (Surg.) One who performs some act upon the human body by means of the hand, or with instruments. [ 1913 Webster ]
3. A dealer in stocks or any commodity for speculative purposes; a speculator. [ Brokers' Cant ] [ 1913 Webster ]
4. (Math.) The symbol that expresses the operation to be performed; -- called also facient. [ 1913 Webster ]
5. A person who operates a telephone switchboard. [ PJC ]
6. A person who schemes and maneuvers adroitly or deviously to achieve his/her purposes. [ PJC ]
n. A laboratory. [ Obs. ] [ 1913 Webster ]