The word "lairy" is an informal British slang term used to describe someone who is loud, brash, or aggressive. Although it is commonly used, there are many other words that can be used to describe someone who exhibits this type of behavior. Some synonyms for the word "lairy" include boisterous, rowdy, obstreperous, noisy, and tumultuous. Other more colloquial synonyms include raucous, unruly, wild, or even "out of control." Each of these words can be used to describe someone who is behaving in a loud, brash, or aggressive manner, and can help to add nuance and depth to your descriptions and writing.