IN Meaning of IN in English I. IN written abbreviation for ↑ Indiana II. In ‧ di ‧ an ‧ a /ˌɪndiˈænə/ BrE AmE written abbreviation , IN a state in the ↑ Midwest of the US, known for its farming Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012