What does unknowable mean?
“Unknowable” describes something that cannot be known or understood, or something that lies beyond the reach of human knowledge. It is especially common in philosophical, scientific, religious, and literary discussion, where it can refer to ultimate realities, hidden causes, distant origins, or complex systems whose full workings cannot be comprehended. The word conveys both uncertainty and a sense of mystery. Unlike “unknown,” which may simply mean not yet discovered, “unknowable” suggests that knowledge might be impossible in principle. It can describe an answer, a truth, a motive, an event, or a force: for example, the consequences of a distant future event may be unknowable. In ordinary conversation, it is more emphatic and formal than expressions such as “we do not know yet.” Its usefulness lies in distinguishing temporary ignorance from a fundamental boundary of human understanding.
adjectiveNot possible to know; beyond the reach of human knowledge or understanding.
- Not possible to know or comprehend, especially because something is beyond the limits of human understanding.
"The origin of the universe may be unknowable."
"Some aspects of the past may remain unknowable because the evidence has disappeared."
"She described the underlying motives of the decision as unknowable."
The unknowable is not merely the unknown: it points to a fundamental limit on what knowledge can ever reveal.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of unknowable
“Unknowable” is an English formation built from the prefix “un-,” the verb “know,” and the suffix “-able.” The construction has long been used to create negative forms of adjectives based on verbs, as seen in words such as “unavoidable” and “unpredictable.” Its development reflects the established English relationship between “know,” “known,” “knowledge,” and related forms, all based on the same Germanic root. The word’s sense of being beyond possible knowledge developed through its regular negative formation.
Related word forms
How unknowable is actually used
The word is formal and often philosophical or literary. It is stronger than “unknown,” suggesting not merely a temporary lack of information but a possible or inherent limit on knowledge.
Easily confused with unknowable
“Unknown” describes something that has not yet been discovered or identified, whereas “unknowable” suggests that it may be impossible to know or understand.