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octillion

/ɑːkˈtɪljən/

A number equal to one followed by 27 zeros

From Greek, via Latin and French oct (eight) + French illion (suffix forming names of large numbers).

noun
adjective
oct
Ancient Greek
AI-inferred
oktō (ὀκτώ)
“eight”; the numeral behind the modern oct- combining form
Latin
AI-inferred
octō
“eight,” borrowed into scientific and learned compounds
French
Verified
oct-
The “eight” element used in the formation of octillion

from French octillion. By surface analysis, oct- (“eight”) +‎ -illion.

illion
French
Verified
-illion
A suffix used in names of very large numbers, modeled on million

from French octillion. By surface analysis, oct- (“eight”) +‎ -illion.

Modern English
Verified
-illion
A productive numerical suffix in million, billion, trillion, and related terms

from French octillion. By surface analysis, oct- (“eight”) +‎ -illion.

Combined
French octillion
French combines oct- (“eight”) with -illion to form the name of a large-number unit.
Modern English
Verified
octillion
A large-number name; in the short scale, 10²⁷, or 1 followed by 27 zeros

from French octillion. By surface analysis, oct- (“eight”) +‎ -illion.

Modern English
octillion

The visible clue in octillion is oct-, the same “eight” hiding in octagon, octave, and octopus—the last named for an animal whose arms look like eight living fingers. French mathematicians formed octillion by attaching that numeral element to the large-number suffix -illion, creating a word that sounds almost modest while naming an absurdly vast quantity. In modern American usage, an octillion is 1 followed by 27 zeros; the name is useful precisely because writing all those zeros turns a sentence into a visual thicket. The suffix itself belongs to a family stretching from million to trillion, so octillion is less a lone giant than one member of a carefully expandable numerical dynasty. Remember the image: oct- supplies the eight, while -illion builds the skyscraper of zeros.

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