overdrive

• POS: Noun, Verb (transitive)
• HYPHEN: o=ver=drive

CIDE DICTIONARY

overdrive, v. t. & i. 

 To drive too hard, or far, or beyond strength.  [1913 Webster]

overdrive, n. 

•  A gearing device which causes the drive shaft of an automobile or other machine to rotate at a speed greater than that of the engine crankshaft.  [PJC]
•  The gear setting of a motor vehicle at which the overdrive{1} is operative; as, cruising at 80 mph in overdrive.  [PJC]
•  A state of unusually intense activity; as, when they got their new supercomputer, their research kicked into overdrive; one look at her made his heart jump into overdrive; -- used mostly of the activities of persons or groups.  [PJC]

OXFORD DICTIONARY

overdrive, n.
1 a a mechanism in a motor vehicle providing a gear ratio higher than that of the usual gear. b an additional speed-increasing gear.
2 (usu. prec. by in, into) a state of high or excessive activity.

THESAURUS

overdrive

Hydromatic, automatic transmission, burden, busy, carry too far, cogwheel, differential, differential gear, drive, exaggerate, exhaust, fag, freewheel, gear, gear train, gearbox, gearing, gearshift, gearwheel, go overboard, go to extremes, go too far, high, intermediate, keep busy, know no bounds, low, neutral, oppress, overact, overcarry, overdevelop, overdo, overelaborate, overemphasize, overexercise, overexert, overexpend, overindulge, overlabor, overplay, overreact, overspend, overstrain, overstress, overstudy, overtask, overtax, overtrain, overuse, overwork, pass all bounds, protest too much, rack, reverse, standard transmission, stick shift, sweat, synchromesh, task, tax, transmission, work