👉 A megohm is a unit of electrical measurement used to measure the electric current through an ohmmeter. It is defined as one thousandth of an ampere-second (A²s). The prefix "mega" means "ten times," so megohms are ten times larger than amperes or watts, which are units of power. The relationship between megohms and other units can be expressed in the following equation: \[ \text{Megohm} = 10