The verb pivot—first used in the mid 1800s‚is defined as follows:
intransitive. To turn on, or as if on, a pivot; (Military) to swing round a central point during a manoeuvre. Also figurative: to depend on, to hinge on.
Oxford English Dictionary
It was based on the noun pivot, fist used in the late 1300s:
A short shaft or pin, usually of metal and pointed, forming the centre on which a mechanism turns or oscillates, as the pin of a hinge, or the end of an axle or spindle; a fulcrum) which was used in the late 1300s.
Oxford English Dictionary
I think what both of these definitions have in common isn’t simply the idea of “turn,” but rather a turn around something: a central point, a pin, a fulcrum.
And that’s one of the key concepts of a career ikigai pivot: you aren’t just turning, you are turning around some fix point—one established upon all of your prior years of experience.