I often flip through a thesaurus when I'm trying to rewrite a line of dialogue for a moody character, and my quick take is: yes, thesauruses do give clear synonyms for 'mope', but they don't always capture the feel you want. They typically list words like 'sulk', 'pout', 'brood', 'gloom', and 'depress', sometimes with short notes for register (informal, literary) or intensity. That list is handy when you're hunting for alternatives, but it can be a trap if you replace blindly.
For example, 'sulk' feels angrier and more active—someone pulling away with a crossed arms vibe—while 'brood' leans introspective and slow, like a character staring at rain and chewing on memories. I always cross-check with usage examples or a quick search in a corpus so my replacement fits the tone and rhythm of the sentence. Thesauruses are a starting map, not the whole territory; they point you toward synonyms, but you still have to walk the streets to know how each one smells in context.