'mho' originates from the word 'ohm', which is the unit of electrical resistance. The term 'mho' is simply 'ohm' spelled backward, indicating its reciprocal nature.

'Mho' was coined as a playful reversal of 'ohm' to represent the reciprocal unit of conductance.

Initially, it was introduced to represent the reciprocal of resistance, and this meaning has remained consistent.