Nitrogen-monoxide, also known as nitric oxide (NO), is an essential compound that plays a significant role in various processes within the environment and human body. Synonymous terms for this compound include nitrosyl radical, nitrogen(I) oxide, and nitrogen monoxide. This gaseous molecule is produced mainly by combustion processes, industrial activities, and natural sources such as lightning and microbial activities. Nitric oxide is a crucial precursor for the formation of nitrogen dioxide (NO2), an air pollutant with adverse health effects. Understanding the diverse synonyms associated with nitrogen-monoxide helps researchers, scientists, and policymakers to effectively communicate and comprehend its impact on atmospheric chemistry and human health.