The word "peakless" refers to something or someone that lacks peaks or points. There are several synonyms for the word "peakless" depending on the context in which it is used. Some of these synonyms include flat, level, smooth, even, featureless, undulating, rolling, gentle, unbroken, and plain. These words are commonly used to describe landscapes or surfaces that are devoid of any prominent elevation or protuberance. The word "peakless" can also be used to describe a person who lacks any outstanding or remarkable qualities. In this case, the synonyms for "peakless" include ordinary, unexceptional, unremarkable, average, and mediocre.