NANO- Meaning of NANO- in English nano- /nænəʊ $ -oʊ/ BrE AmE prefix [in nouns] [ Language: Greek ; Origin: nanos 'dwarf' ] one ↑ billion th part of a unit:nanometre (=a billionth of a metre) Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012