There are a variety of synonyms that can be used for the word "Rainer". Some of the most common synonyms include "rainy", "showery", "damp", "drizzly", "mizzly", and "wet". These words all describe conditions that involve precipitation in some form, and are often used interchangeably to describe the weather. Other synonyms for "Rainer" might include words like "moist", "drenched", or "soaked", which describe conditions that are wet or damp due to rainfall or other sources of moisture. Whatever the synonym used, the most important thing is to accurately convey the weather conditions that are being experienced.