What does ascertainably mean?
Ascertainably is a formal English adverb meaning 'in a way that can be determined or verified with certainty.' It derives from the verb 'to ascertain,' which itself traces back through Old French to the Latin certus, meaning 'settled' or 'sure.' The adverb is rare in casual conversation but finds a natural home in legal, academic, and technical writing, where writers need to signal that a fact is not merely assumed but genuinely capable of being established. A sentence such as 'the error was ascertainably introduced during transcription' conveys that the mistake can be verified beyond dispute. Its register is distinctly formal, and it often appears in negative or qualified constructions — 'not readily ascertainably' — to flag claims whose truth cannot be pinned down. For readers who enjoy precise instruments of language, it offers an efficient way to distinguish between what is known and what merely seems plausible.
adverbIn a manner that can be determined or established with certainty; in a way that is capable of being found out as true.
- In a manner capable of being determined or verified as certain; such that it can be found out.
"The committee concluded that the funds had, ascertainably, been misallocated over the previous fiscal year."
"The auditor confirmed that the discrepancies were ascertainably the result of data-entry errors."
"Whether the manuscript predates the fire remains ascertainably uncertain."
It's the lawyer's favorite adverb: when 'ascertainably' appears in legal writing, someone's facts are about to be held to account.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of ascertainably
Ascertainably derives from the verb 'ascertain,' which entered English in the late Middle English period (by the 15th century) from Anglo-Norman and Old French acertainer, formed on the Late Latin certificare-influenced root certus ('settled, sure'). The adverbial form arose later by adding the standard '-ly' suffix, following the pattern of other verbs-turned-adverbs. It shares its ultimate Latin root with words like 'certain,' 'certainty,' and 'certificate.'
Related word forms
How ascertainably is actually used
Formal and somewhat rare; most frequent in legal, academic, and technical prose where precision about verifiability matters. In everyday speech, speakers typically rephrase using 'can be determined' or 'verifiably'.
Easily confused with ascertainably
'Ascertain' is the verb meaning to find out or determine something for certain, while 'ascertainably' is its adverbial form describing something that can be so determined.