'overdrive' definitions:

Definition of 'overdrive'

(from WordNet)
noun
The state of high or excessive activity or productivity or concentration; "Troops are ready to go into overdrive as soon as the signal is given"; "Melissa's brain was in overdrive"
noun
A high gear used at high speeds to maintain the driving speed with less output power
verb
Drive or work too hard; "The teacher is overworking his students"; "Overdriving people often suffer stress"
verb
Make use of too often or too extensively [syn: overuse, overdrive]

Synonyms of 'overdrive'

From: Moby Thesaurus