In other countries, the term aircraft commander is used instead of acting as PIC.
[GEEK WARNING]
The term for the "type of time required to meet FAA certificate, rating and currency requirements" it has changed from time to time in the US. The use of sole manipulator time, then referred to as "solo" ("solo" as "sole occupant" shows up in the 1950s) seems to have made its appearance as early as the late 1920s although at that time is was required to be both "the sole operator of the controls
and ... in command of aircraft in flight" (my emphasis).
The current version of the rule, still using "solo" instead of PIC and dropping the need to actually be the pilot in command seems to make its first appearance in a 1942 revision to Part 20 of the CAR, adding a new rule on logging:
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20.673 Logging of pilot flight time.*
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(b) The holder of a pilot certificate, other than a student pilot certificate, may log as solo flight time that portion of any flight during which he is the sole manipulator of the controls: Provided, That he may log as solo flight time only 50 percent of any flight time during which a certificated instructor or a certificated airline transport pilot is in the aircraft serving as an instructor for the purpose of reviewing or increasing such pilot's skill;
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Change "solo flight time" to "pilot in command" and, except for removing the instruction debit and adding some more requirements, you have the rule in essentially the same form today as it has been for the past 70+ years.
And we still argue about it as though someone made it up yesterday.
(Yes, I need a life - my only excuses are (1) inborn academic curiosity and (2) being laid-up after hip surgery. Most of this post is a copy and paste of one I did years ago)