one hundred-thousandth
Obscure numeric unit; not used in modern Japanese. Equivalent to 1/100,000.
adverb taking the 'to' particle
Obsolete adverbial use, typically in the form 忽として. The cross-referenced word 忽然 (こつぜん) is the modern equivalent.
See also: 忽然
The character 忽 is sometimes used in old texts as a unit meaning one hundred-thousandth.
In classical literature, 忽として was used to mean 'suddenly'.