[1] : The Collaborative International Dictionary of English v.0.48

circumstance \cir"cumstance\ s~er"ku^msta^ns, n. l.
   circumstantia, fr. circumstans, -antis, p. pr. of circumstare
   to stand around; circum + stare to stand. see stand.
   1. that which attends, or relates to, or in some way affects,
      a fact or event; an attendant thing or state of things.
      1913 webster

            the circumstances are well known in the country
            where they happened.                  --w. irving.
      1913 webster

   2. an event; a fact; a particular incident.
      1913 webster

            the sculptor had in his thoughts the conqueror
            weeping for new worlds, or the like circumstances in
            history.                              --addison.
      1913 webster

   3. circumlocution; detail. obs.
      1913 webster

            so without more circumstance at all
            i hold it fit that we shake hands and part. --shak.
      1913 webster

   4. pl. condition in regard to worldly estate; state of
      property; situation; surroundings.
      1913 webster

            when men are easy in their circumstances, they are
            naturally enemies to innovations.     --addison.
      1913 webster

   not a circumstance, of no account. colloq.

   under the circumstances, taking all things into
      consideration.

   syn: event; occurrence; incident; situation; condition;
        position; fact; detail; item. see event.
        1913 webster
see also:
stand not a circumstance under the circumstances event 

[2] : WordNet (r) 2.0

under the circumstances
     adv : because of prevailing conditions; "under the circumstances i
           cannot buy the house"

Circumstances >> C Words
Circumstances, definition of term: Circumstances
circumstances_pag1.html

Go Under >> G Words
Go Under, definition of term: Go Under
go+under_pag1.html