a positive photographic image on a transparent material, as a photographic slide or lantern slide
diapositive in American English
(ˌdaiəˈpɑzɪtɪv)
noun
a positive photographic image produced on a transparent film or glass base
Word origin
[1890–95; dia- + positive]This word is first recorded in the period 1890–95. Other words that entered Englishat around the same time include: bootstrap, phoneme, plein-air, pogey, wirelessdia- is a prefix occurring in loanwords from Greek (diabetes; dialect) and used, in the formation of compound words, to mean “passing through” (diathermy), “thoroughly,” “completely” (diagnosis), “going apart” (dialysis), and “opposed in moment” (diamagnetism)