ETYM From Michael Faraday, the English electrician.
The unit of capacitance (the ability to hold a charge). A 1-farad capacitor holds a charge of 1 coulomb with a potential difference of 1 volt between its plates. In practical use, a farad is an extremely large amount of capacitance; capacitance is usually expressed in terms of microfarads (10–6) or picofarads (10–12). Abbreviation: F.
Unit measuring electrical capacitance.
The capacitance of a capacitor that has an equal and opposite charge of 1 coulomb on each plate and a voltage difference of 1 volt between the plates; SYN. F.
Unit of electrical capacity: capacity of condenser, charged with one coulomb, giving potential difference of one volt.
SI unit (symbol F) of electrical capacitance (how much electricity a capacitor can store for a given voltage). One farad is a capacitance of one coulomb per volt. For practical purposes the microfarad (one millionth of a farad) is more commonly used.
The farad is named for English scientist Michael Faraday, and replaced the now obsolete unit the jar (so called because it represented the charge stored in a Leiden jar, the earliest electrical circuit). One farad equals 9 × 108 jars.