rotary drill[′rōd·ə·rē ′dril]
Any of various drill machines that rotate a rigid, tubular string of rods to which is attached a rock cutting bit, such as an oil well drilling apparatus.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
A machine for opening holes in rock or earth by means of a cutting bit at the end of a metal shank; usually turned by a hydraulically or pneumatically driven motor.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.