Plain English Meaning
The turn that brings you back toward the fix you are holding over, after you have flown away from it. It points the airplane back the way it came so the next leg leads to the fix.
Full Definition
In a holding pattern, the turn made at the end of the outbound leg that reverses the aircraft's direction and aligns it back toward the holding fix on the inbound course. It is normally a 180-degree turn flown in the direction specified by the holding instruction (standard right turns unless otherwise issued).
Context Anchor
Seen when flying IFR holding patterns, especially when timing or correcting the outbound leg before turning back toward the holding fix.