Prima facie is a Latin expression meaning "at first sight", or "based on first impression". The literal translation would be "at first face" or "at first appearance", from the feminine forms of primus ("first") and facies ("face"), both in the ablative case. In modern, colloquial, and conversational English, a common translation would be "on the face of it".

Evidence for a proposition is what supports the proposition. It is usually understood as an indication that the supported proposition is true. What role evidence plays and how it is conceived varies from field to field.