* Rhyming is subjective: What sounds like a rhyme to one person might not to another. Some rhymes are more "perfect" than others, and the "closeness" of the rhyme can be debatable.
* The English language is constantly evolving: New words are created and old words take on new meanings all the time. This can change how words rhyme over time.
* Regional accents: Different accents can change the pronunciation of words, affecting how they rhyme.
However, there are some words that are notoriously difficult to find rhymes for in English, such as:
* Orange: This is often cited as an example of a word with no perfect rhyme.
* Purple: Similar to orange, this word also lacks a perfect rhyme.
* Month: Many consider this word to have no true rhyme in English.
Instead of trying to find words that *don't* rhyme, it's often more productive to focus on finding words that *do* rhyme. There are plenty of resources available to help you with this, such as rhyme dictionaries and online rhyme generators.