The term 'LESS SLACK' can be summarized by the crossword solution 'TAUTER', which is a six-letter word meaning 'tighter, firmer, or more rigid'. This term is often used to describe a situation in which there is less room for error or less flexibility. It can also refer to a situation in which there is less time or resources available. In either case, it implies that the situation is more demanding and requires greater attention to detail.