The prefix 'WITHIN' is used to describe something that is located inside or WITHIN a certain area. The crossword solutions for the term 'WITHIN' are ESO (3 letters), ENDO (4 letters), ENTO (4 letters), ENT (3 letters), and INTRA (5 letters). ESO stands for 'ESOPHAGUS, ' which is the tube that connects the throat to the stomach. ENDO stands for 'endogenous, ' which means something that originates from WITHIN an organism. ENTO stands for 'entomology, ' which is the study of insects. ENT stands for 'ENTRANCE, ' which is a way of entering a place. Finally, INTRA stands for 'intramural, ' which refers to activities that take place WITHIN a certain group or organization.