overhead projector
noun /ˌəʊvəhed prəˈdʒektə(r)/
/ˌəʊvərhed prəˈdʒektər/
(abbreviation OHP
/ˌəʊ eɪtʃ ˈpiː/
/ˌəʊ eɪtʃ ˈpiː/
)- a piece of equipment that projects an image onto a wall or screen so that many people can see it
- I gave that talk back in the days of overhead projectors and transparencies.