| electrostatic unit | |
| —n | |
| Compare electromagnetic unit ESU, Abbreviation: e.s.u. any unit that belongs to a system of electrical cgs units in which the electric constant is given the value of unity and is taken as a pure number | |
| a calculus or concretion found in the stomach or intestines of certain animals, esp. ruminants, formerly reputed to be an effective remedy for poison. |
| a chattering or flighty, light-headed person. |