I was lamenting the use of "semaphore" but wikipedia supports them: > Semaphore (lit. 'apparatus for signalling'; from Ancient Greek σῆμα (sêma) 'mark, sign, token', and Greek -φόρος (-phóros) 'bearer, carrier')[1] is the use of an apparatus to create a visual signal transmitted over distance. https://en.m.wikipedia.org/wiki/Semaphore I was only familiar with: > [A semaphore] is a variable or abstract data type used…
The Portuguese and Spanish word for it, semáforo, is what traffic lights are called at least in parts of Latin America. I always interpreted the programming meaning as that - traffic lights.
Moving arms also predate traffic lights for the same function - see trains https://en.wikipedia.org/wiki/Railway_semaphore_signal