INFRA- Meaning of INFRA- in English infra- /ɪnfrə/ BrE AmE prefix technical [ Language: Latin ; Origin: infra 'below' ] below something in a range:the infra-red end of the spectrum ⇨ ↑ ultra- (2) Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012