a high gear used at high speeds to maintain the driving speed with less output power
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"
drive or work too hard; "The teacher is overworking his students"; "Overdriving people often suffer stress"
enlarge, develop, or increase by degrees or in stages; "build up your savings"
change the use of and make available or usable; "develop land"; "The country developed its natural resources"; "The remote areas of the country were gradually built up"
form or accumulate steadily; "Resistance to the manager's plan built up quickly"; "Pressure is building up at the Indian-Pakistani border"
bolster or strengthen; "We worked up courage"; "build up confidence"; "ramp up security in the airports"