"Languid" is an adjective, and "languish" is a verb.

Try this one: moving or speaking slowly with little energy, often in an attractive way: a languid manner/voice. Synonyms languorous literarylethargiclistlesstorpid formal Opposites dynamic (FULL OF ENERGY)energetic. I hope it's a lot clearer now.

Some thoughts... 1. "Languid" (adjective): describes things with low energy. 2. "Languishing" (verb): usually describes ongoing suffering 3. "Languishing" is probably used more than "languid." 4. Neither word is used much in daily speech. I almost never use "languid." I use "languishing" maybe 5-10 times a year.