Logo
dictionary thesaurus

atto-

combining form
at·​to- | \ ˈa-(ˌ)tō\

Definition of atto-

: one quintillionth (10−18) part of attogram

History and Etymology for atto-

International Scientific Vocabulary, from Danish or Norwegian atten eighteen, from Old Norse āttjān; akin to Old English eahtatīene eighteen

Keep scrolling for more

WORD OF THE DAY

progeny

play

See Definitions and Examples

Get Word of the Day daily email!