soured

The word 'soured' is built upon the Germanic root sūr-, which carries the core meaning of "acidic" or "tart," a taste sensation. This root is ancient, traceable to Proto-Germanic sūraz and likely further back to a Proto-Indo-European root meaning "salty, bitter, sour." The addition of the '-ed' suffix, a common Germanic participial ending, transforms the base word into an adjective describing the state of having undergone the process of becoming sour. Thus, the literal meaning "made acidic" evolved metaphorically to describe relationships that have turned bitter or situations that have deteriorated, perfectly linking the physical sensation to an abstract emotional or qualitative state.

Structure: sour (acidic, tart) + ed (adjective suffix, indicating state or condition) - sour: From Old English sūr, of Germanic origin; related to Dutch zuur and German sauer. Functions as the core adjective/verb root meaning "having an acid taste" or "to become acid". - ed: From Old English -ed, -od, -ad, a past participle suffix used to form adjectives indicating a state resulting from an action (e.g., "turned sour").