Definition of ear-to-ear in English:

ear-to-ear

adjective

  • Stretching right across the face or neck, as if from one ear to the other; specifically (of a grin or smile) broad, wide.

adverb

  • Right across the face, head, or neck; from (or as if from) one ear to the other.

Origin

Late 19th century; earliest use found in The Titusville Morning Herald. From ear + to + ear, after from ear to ear.

Pronunciation

ear-to-ear

/ˌɪətəˈɪə/