喊 (hǎn) means 'to shout, yell, call out loudly' — it emphasizes a loud voice, often to get someone's attention from a distance or in an urgent situation. It is stronger and more forceful than 叫 (jiào), which can also mean 'to call' but is not necessarily loud and has many other uses (e.g., 'to be called', 'to ask someone to do something'). The other siblings (呼, 呼唤, 嚷, 呐喊) are more formal or literary and less common in everyday speech.