electrical engineering

https://en.wikipedia.org/wiki/Three-phase

After a lifetime in the field, Rang, I must report that I don't remember any such idiom. I'd guess it's the current flowing in a single phase

However I only admit my incredible ignorance after Googling. I'd fwd a link but this morning Mac refuses me adds.

In title listing however, Rang, the expr is "load current," a more familiar term referring to current for the device being powered

The OP doesn't really fully define any question. If I had to guess, I'd say it was related to power factor, where current is out of phase with the voltage due to either capacitive or inductive load. But its anybody's guess.

Good guess, Lead

Phase you mean 1 phase of a multi-phase line. Phase current is flow between phase to neutral is called phase current.