plausibly

Plausibly is an adverb that describes something as believable or credible, though not certain. It is used to indicate that a claim, explanation, or scenario could reasonably be accepted as true given available information, while leaving room for doubt.

Etymology and form: Plausibly derives from the adjective plausible, which comes from Latin plausibilis, meaning worthy of applause or acceptable. The adverbial suffix -ly attaches to convey manner or degree, as with many English adverbs.

Usage and nuance: In formal and analytic writing, plausible is used to flag a claim as credible but not definitively proven. Plausibly can modify verbs or clauses, as in “The theory explains the data plausibly” or “Plausibly, the policy would reduce costs.” The phrase plausibly deniable is a common collocation, describing actions that could be denied with a reasonable explanation. Distinguishing plausibility from probability is important: something can be plausible without being demonstrated or verified, and something highly probable may still be incorrect if new evidence emerges.

Limitations and context: Plausibility depends on perspective, information, and assumptions. Evaluations of plausibility can reflect biases, and what seems plausible in one domain (e.g., everyday reasoning) may be less so in rigorous scientific or legal contexts. In philosophy and rhetoric, plausibility is often weighed alongside evidence, coherence, and falsifiability rather than treated as a substitute for them.

Related terms: plausible (adjective), plausibility (noun), and the related idiom plausibly deniable. In discourse, plausibility serves as a hedging device that communicates reasonable belief without asserting certainty.