The story
PIE word *sḗh₂l From weak (adjective) + sauce (noun), referring to a sauce that lacks flavour. By surface analysis, weak + -sauce (suffix used to add emphasis to adjectives).
First known use, by meaning
- from late 1980s Lacking in interest or substance; boring, disappointing, lackluster.
Etymology from Wiktionary, CC BY-SA 4.0.