The word "strain" generally refers to a pressure or stress applied to something, often resulting in distortion or tension. It can also mean to exert effort, particularly in physical or mental tasks. In a biological context, it can refer to a specific variety or type of organism, particularly in relation to bacteria or viruses.
The word "strain" comes from the Latin "stringere," which means to draw tight or bind. It entered Middle English through the Old French form "estraindre," reflecting a sense of stretching or exertion.