Adverse happening can be defined as an unexpected or unfortunate event that can cause harm or damage to individuals or things. There are several synonyms for the word "adverse happening," including calamity, disaster, misfortune, setback, crisis, and catastrophe. These words are used to describe unexpected events that can have devastating consequences, whether it be a natural disaster like an earthquake or a man-made crisis like a financial collapse. The use of synonyms helps writers to describe such events with more precision and nuance, and helps readers to understand the gravity of the situation being described. Ultimately, the synonyms for "adverse happening" can help us to better comprehend the world around us, and prepare for the unexpected.