The term 'Smelling a Rat' is an idiom which means to be suspicious of something or someone. It is derived from the idea that rats have a keen sense of smell and can detect danger before humans can. The crossword solution for this term is 'LEERY', which means to be cautious or wary of something. Therefore, the phrase 'Smelling a Rat' and the crossword solution 'LEERY' both refer to being suspicious or cautious of something.