The term 'least important' can be described by three words with nine, eight, and eight letters respectively: SLIGHTEST, LITTLEST, and SMALLEST. These words all refer to the idea of something being of minimal importance or significance. SLIGHTEST implies that something is barely noticeable or has a small impact, while LITTLEST suggests that something is very minor or insignificant. Finally, SMALLEST implies that something is of the lowest degree or magnitude. All three words can be used to describe something that is of the least importance.