What does "earphone" mean?

A transducer that converts electric signals into sound and is held near the ear, especially as part of a telephone; an earpiece or headphone.

How do you pronounce "earphone"?

Pronounced //ˈɪə(ɹ)fəʊn//.

Common synonyms include: earpiece, acoustical network, audiometer earphone, capacitor speaker, coaxial speaker, cone.

/ˈɪə(ɹ)fəʊn/ noun

noun ·Uncommon ·Advanced level

Noun

1
A transducer that converts electric signals into sound and is held near the ear, especially as part of a telephone; an earpiece or headphone.
2
electro-acoustic transducer for converting electric signals into sounds; it is held over or inserted into the ear wordnet

"He was listening to the radio with his earphone."

From ear + phone.