Mawson, C.O.S., ed. (1870–1938). Roget’s International Thesaurus. 1922.
Class I. Words Expressing Abstract RelationsSection VI. Time
2. Relative Time
1. Time with reference to Succession
119. [Time Different from the Present.] Different time.
[INDEFINITE TIME] aorist.
WHEN; whenever, whensoever; whereupon, upon which, on which occasion; at another time, at a different time, at some other time, at any time; at various times; some of these days, one of these days, some fine morning, one fine morning; some fine day, on divers occasions, sooner or later; some time or other.
ONCE, formerly, once upon a time.