microdot
- n photograph reduced to the size of a dot (usually for purposes of security)
- Curiously enough, police searching Helen Kroger's handbag had found a microdot message from Lonsdale's wife and a six-page handwritten letter in Russian from Lonsdale in reply.
- Their modest home was littered with the latest espionage devices, ranging from microdot readers to long-range radio-transmission equipment.
- Along with $6,500 and a promise of a monthly $500 retainer, he was given a miniature tape recorder, secret writing paper and a deciphering code for microdot messages.