the word tendonitis is a modern medical term constructed from classical components. its first element, tendon, originates from the greek tenōn, meaning "sinew" or "that which stretches," derived from the verb teinein (to stretch), which reflects the tendon's functional property. the suffix -itis is borrowed directly from greek, where it originally formed adjectives from nouns ending in -itēs but was adopted into new latin as a standard suffix for naming inflammatory diseases. the compound thus follows a transparent anatomical-pathological formula, literally meaning "inflammation of the tendon," which directly and logically describes the medical condition. this pattern of combining a body part with -itis is prolific in medical terminology, creating words like arthritis and bronchitis.

Structure: tendon (cord-like tissue) + itis (inflammatory disease) tendon: from medieval latin tendon-, tendo, from greek tenōn (tendon, sinew), from teinein (to stretch). functions as the base noun specifying the anatomical structure affected. itis: from modern latin, from greek -itis, a suffix forming nouns denoting diseases characterized by inflammation. functions as a suffix indicating a pathological condition.