Stand in is a term used to describe someone who temporarily takes the place of another person. The three crossword solutions for this term are DEPUTISE (8 letters), LOCUM (5 letters), and PROXY (5 letters). DEPUTISE is a verb meaning to act as a deputy or SUBSTITUTE for someone else. LOCUM is a noun meaning a doctor or other professional who temporarily takes the place of another. PROXY is a noun meaning the authority to represent someone else, such as in voting.