Definition of roasting ear in US English:

roasting ear

noun

US
  • An ear of maize or sweetcorn suitable for cooking, especially by roasting. Also in "to be in roasting ear": (of maize) to be ripe for harvest; to be suitable for cooking.

Origin

Mid 17th century. From roasting + ear.

Pronunciation

roasting ear

/ˈrəʊstɪŋ ˌɪə/