The word 'switchgrass' is a transparent English compound formed from two native elements. The first element, 'switch', originally referred to a thin, flexible twig or rod, a meaning that persists in phrases like 'a switch from a tree'. This term was applied descriptively to the plant due to its slender, wand-like stems and seed heads. The second element, 'grass', is the fundamental Germanic word for the family of plants. Thus, the name 'switchgrass' literally means 'a grass resembling a slender switch', a direct reference to its distinctive physical form and growth habit, distinguishing it from other, broader-leaved or bushier grasses.

Structure: switch + grass - switch: Likely from English dialectal 'switch' (a slender, flexible shoot or twig), of uncertain origin, possibly related to a Germanic base meaning 'to swing' or 'to bend'. In this compound, it functions as a descriptive modifier. - grass: From Old English 'græs' (herb, plant, grass), from Proto-Germanic grasą. It functions as the head noun, denoting the primary category of the plant.