operatory

Etymology
Originally from, from a participle of. The modern senses may be derived independently of the obsolete senses.

Adjective

 * 1)  effective; practical; operative 1
 * 2) Of or relating to operations.

Noun

 * 1)  A laboratory. 1
 * 2)  A room in which a dentist (or assistant) performs tasks on the patient. 1