Definitions:

1. any agent, such as a person, animal, or microorganism that carries and transmits a disease noun
   • The scientists pinpointed the mosquito as a transmitter of the disease.
2. set used to broadcast radio or TV signals noun
   • The transmitter was perched high on a hill in order to reach all households.
3. someone who transmits a message noun
   • The transmitter cycled through the streets to deliver the important letter.

Synonyms:

• sender
• vector