[1940–45; photo- + reconnaissance]This word is first recorded in the period 1940–45. Other words that entered Englishat around the same time include: Rh factor, blockbuster, set-aside, whiteout, zapphoto- is a combining form meaning “light” (photobiology); also used to represent “photographic” or “photograph” in the formation of compoundwords. Other words that use the affix photo- include: photochronograph, photocoagulation, photogenic, photolithography, photorealism