soundly
UK: ˈsaʊndli | US: ˈsaʊndli
adv. in a thorough or undisturbed manner (e.g., sleep soundly)
adv. in a firm or reliable way (e.g., argue soundly)
adv. healthily or robustly (e.g., built soundly)
soundly = sound<healthy/firm> + ly<adverb suffix>
- sound (from Old English gesund "healthy, safe") evolved to mean "solid, reliable" (e.g., sound advice) and "deep/undisturbed" (e.g., sound sleep).
- ly (from Old English -līce), a common adverbial suffix indicating manner.
Etymology Origin:
The word traces back to Old English gesund, reflecting physical health and stability. Over time, "sound" expanded metaphorically to describe reliability (e.g., "sound logic") and undisturbed states (e.g., "sound sleep"). The suffix -ly systematically turns adjectives into adverbs, preserving the core meaning while modifying grammatical function.
The baby slept soundly through the night.
The team was soundly defeated in the final match.
The bridge was soundly constructed to withstand earthquakes.
She argued soundly, leaving no room for doubt.
The old oak tree still stands soundly after centuries.