Keywords:  infer, jury, indirect, prove, evidence
Indirect evidence that implies something occurred but doesn't directly prove it. If a man accused of embezzling money from his company had made several big-ticket purchases in cash around the time of the alleged embezzlement, that would be circumstantial evidence that he had stolen the money.
This is trial evidence that is not directly from an eyewitness or participant in the events. In other words, the facts can only be proven using some reasoning.
Evidence which may allow a judge or jury to deduce a certain fact from other facts which have been proven. In some cases, there may be evidence essential to prove a case that cannot be proven directly, such as with an eye-witness. In these cases, the lawyer will provide the judge or juror with evidence of the circumstances from which a juror or judge can logically deduct, or reasonably infer, the fact that cannot be proven directly; it is proven by the evidence of the circumstances; hence, "circumstantial" evidence. Fingerprints are an example of circumstantial evidence: while there may be no witness to a person's presence in a certain place, or contact with a certain object, the scientific evidence of someone's fingerprints is persuasive proof of a person's presence or contact with an object.