ATTOSECOND
Meaning of ATTOSECOND in English
at ‧ to ‧ sec ‧ ond /ˈætəʊˌsekənd $ -toʊ-/ BrE AmE noun [countable] technical
a unit of time that is equal to 10 to the power of ↑ minus 18
Longman Dictionary of Contemporary English.
Longman - Словарь современного английского языка.
2012