At Heel' is a term used to describe someone who follows closely behind another person. It is often used in the context of a servant or assistant who accompanies their employer or superior. The term can also be used to describe a dog that walks closely beside its owner. The crossword solution for this term is 'STILETTO, ' which refers to a type of shoe with a long, thin heel. Stilettos are known for their elegance and style, but they are also notoriously uncomfortable to wear.