MICROSECOND Meaning of MICROSECOND in English mi ‧ cro ‧ sec ‧ ond /ˈmaɪkrəʊˌsekənd $ -kroʊ-/ BrE AmE noun [countable] one millionth of a second Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012