THESAURUS
upon
about, above, after which, against, anent, apropos of, as for, as regards, as respects, as to, atop, by, by dint of, by means of, by use of, by virtue of, by way of, concerning, en route to, headed for, hereby, hereinafter, herewith, in connection with, in contact with, in passage to, in point of, in re, in reference to, in regard to, in relation to, in relation with, in respect to, in transit to, in virtue of, of, on, on route to, on top of, opposite, over, over against, per, pertaining to, pertinent to, re, referring to, regarding, relating to, relative to, respecting, speaking of, thanks to, thereby, therewith, through, to, touching, toward, towards, up, up against,
upon which, versus, vis-a-vis, whereat, whereby, wherefore, whereon, whereto, whereunto, whereupon, wherewith, wherewithal, with, with regard to, with respect to
ROGET THESAURUS
upon
Different time
N
different time, other time, aorist, aoristic, indefinite, at that time, at which time, at that moment, at that instant, then, on that occasion,
upon, not now, some other time, when, whenever, whensoever,
upon which, on which occasion, at another time, at a different time, at some other time, at any time, at various times, some one of these days, one of these days, one fine morning, eventually, some day, by and by, sooner or later, some time or other, once
upon a time.