The term 'Aqueduct Actions' refers to the activities that take place at an aqueduct, which is a structure built to transport water from one place to another. BETS, a four-letter solution to this crossword, is an acronym for 'Building, Engineering, Testing, and Surveying, ' which are all activities that take place at an aqueduct. These activities involve constructing the aqueduct, ensuring its structural integrity, testing its performance, and surveying the surrounding area.