The term 'slightest amount' can be represented by several different words, each with five or four letters. An OUNCE is a unit of measurement for weight, and it is the smallest unit of measurement in the imperial system. BEANS are a type of legume, and the LEAST amount of BEANS would be a TRACE, which is an extremely small amount. LEAST is another word for the smallest amount, and WHIT is a very small amount of something. A HINT is a clue that implies something without being explicit, and an IOTA is an extremely small amount. All of these words represent the slightest amount of something.