The crossword solution for the term 'PREFIX WITH 'ACT' OR 'PLAY'' is INTER, which is a five-letter word. INTER is a prefix that can be used to form words such as interact, interactivity, interactional, and interplay. It is derived from the Latin word INTER, meaning between or among. When used with the words act or play, it implies an action or activity that involves two or more people or entities. For example, interactive play involves two or more people playing together, while interactive acting involves two or more actors performing a scene together.