1. the refusal to accept or comply with something; the attempt to prevent something by action or argument.

2. the ability not to be affected by something, especially adversely.

3. the impeding, slowing, or stopping effect exerted by one material thing on another.

4. the degree to which a substance or device opposes the passage of an electric current, causing energy dissipation. Ohm’s law resistance (measured in ohms) is equal to the voltage divided by the current.
a resistor or other circuit component which opposes the passage of an electric current.