The term 'single circuit' can be summarized as a type of electrical system in which there is only one path for the current to flow. This is in contrast to a multi-circuit system, which has multiple paths for the current to flow. The crossword solution for this term is 'LAP', which stands for 'Looped Alternating Path'. This refers to the fact that in a single circuit system, the current will loop back and forth between two points, creating an alternating path.