The noun circumstance has 4 senses (first 3 from tagged texts)
1. (39) circumstance -- (a condition that accompanies or influences some event or activity)
2. (8) context, circumstance -- (the set of facts or circumstances that surround a situation or event; "the historical context")
3. (3) circumstance, condition, consideration -- (information that should be kept in mind when making a decision; "another consideration is the time it would take")
4. circumstance -- (formal ceremony about important occasions; "pomp and circumstance")