Meaning of ATTO- in English

ATTO-

¦ad.(ˌ)ō, ¦atə combining form

Etymology: International Scientific Vocabulary, from Danish or Norwegian atten eighteen (from Old Norse āttjān ) + - o - — more at eighteen

: one quintillionth (10 -18 ) part of

atto gram

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.