Definition of phototachymeter in US English:

phototachymeter

noun

  • An optical form of tachymeter.

Origin

1970s; earliest use found in Soviet Journal Optical Technology. From photo- + tachymeter, after Russian svetodal′nomer.

Pronunciation

phototachymeter

/ˌfəʊtəʊtəˈkɪmɪtə/