The word 'stroma' entered English in the mid-19th century as a scientific term, borrowed directly from Latin, where it meant "a bed covering" or "mattress." Latin acquired it from the Greek 'strōma' (στρῶμα), meaning "anything spread out for lying or sitting on," such as a bed, blanket, or mattress. This Greek noun derives from the verb 'stornynai' (στόρνυναι), "to spread out" or "to strew." The semantic evolution from a physical layer spread out as a foundation to the supportive, non-functional matrix of biological tissue is a clear metaphorical extension, visualizing the stroma as the foundational "bed" upon which the specific functional cells operate.

The word 'stroma' is a simplex loanword from Latin, which itself borrowed it directly from Greek. It is not productively segmented into smaller, meaningful morphemes in modern English spelling.