▪ I. ˈsupercharge, n.
[super-1 3, 10.]
1. Her. A charge borne upon another charge. rare.
| 1766 Porny Elem. Her. (1777) T viij b/2. 1780 Edmondson Heraldry II. Gloss., Super-charge, is a term that hath been applied by some to express one figure borne on another... N. B. This word, Super-charge, is now seldom or ever used, surmounted being a better term. |
2. An excessive charge; an overcharge. rare.
| 1826 Disraeli in Monypenny Life (1910) I. vii. 95, I generally detect the aubergiste in a super-charge. |
3. Engin. An explosive charge of higher than usual pressure in the cylinders of an internal-combustion engine; increased pressure of the charge.
| 1912 E. Butler Evol. Internal Combustion Engine vi. 69 It has been proposed by Clerk and others to employ super-compression of the charge.., the combustion cylinder thereby receiving a super-charge of air. 1948 Petroleum Handbk. (Shell Petroleum Co. Ltd.) (ed. 3) xxv. 356 The extra fuel has a certain cooling effect, and this permits an increase in boost (degree of supercharge). 1971 L. J. K. Setright Power to Fly v. 120 The immediate effect of the new fuel was to allow a greater degree of supercharge. |
▪ II. ˈsupercharge, v. Engin.
[super- 9 b.]
trans. To increase the pressure of the fuel-air mixture in (an internal-combustion engine).
| 1919 W. J. Walker tr. Devillers's Automobile & Aero Engines xxiv. 384 Each compressor, having two compression strokes per revolution, can supercharge two cylinders. 1924 Glasgow Herald 6 May 4 The proposition of super-charging engines for sea-going and for road as well as for air service. 1966 McGraw-Hill Encycl. Sci. & Technol. VII. 208/2 Supercharging a two-cycle diesel engine requires some means of restricting or throttling the exhaust in order to build up cylinder pressure. |