Real Dictionary

surge
A surge is a sudden large increase in something that has previously been steady, or has only increased or developed slowly.
If you feel a surge of a particular emotion or feeling, you experience it suddenly and powerfully.
countable noun: A surge is a sudden powerful movement of a physical force such as wind or water.
verb: If a crowd of people surge forward, they suddenly move forward together.
verb: If a physical force such as water or electricity surges through something, it moves through it suddenly and powerfully.
verb: If an emotion or sensation surges in you or through you, you feel it suddenly and powerfully.
verb: If something surges, it increases suddenly and greatly, after being steady or developing only slowly.

surge in American English
a large mass of or as of moving water; wave; swell; billow
noun: a strong, wavelike, forward movement, rush, or sweep

surge in British English
noun: a strong rush or sweep; sudden increase
verb: (of waves, the sea, etc) to rise or roll with a heavy swelling motion

surge in Electrical Engineering
noun: A surge is a momentary wave of current or power in an electric circuit.