What does confirm mean?
To confirm is to make something certain — either by verifying that it is true or by giving it formal, official approval. The verb covers two closely related acts: establishing facts beyond doubt (as when new evidence confirms a scientific hypothesis) and acknowledging or ratifying arrangements (as when a traveller confirms a flight booking or a legislature confirms an appointment). Derived from the Latin confirmare, built on firmus meaning "firm" or "strong," the word literally means "to make firm." It is neutral in tone, at home in both casual conversation and formal legal writing, and is among the most common verbs of verification in English. Related forms include confirmation (the act or ceremony of confirming) and confirmed (established as true, or, of a habit, long-standing). Because so much modern life runs on appointments, bookings, and agreements requiring explicit acknowledgement, confirm remains one of the most practical words in everyday English.
To establish the truth or certainty of something; to verify.
"Carbon dating confirmed the manuscript's age."
Often followed by a that-clause: "She confirmed that the meeting was cancelled."
To formally acknowledge or ratify an arrangement, appointment, or agreement.
"The committee voted to confirm her nomination."
In legal and governmental contexts, this sense implies official sanction.
When you confirm something, you literally make it "firm" — the word carries fifteen centuries of Latin inside it, from firmus, meaning strong and unshakable.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of confirm
Confirm comes from the Latin verb confirmare, formed from com- (an intensive prefix) plus firmare, "to make firm," itself rooted in firmus, "strong, steadfast." The word passed into Old French before entering Middle English in the medieval period, retaining both its literal sense of strengthening and its ecclesiastical sense relating to the sacrament of confirmation. Its cognates include affirm, infirm, and firmament, all descendants of the same Latin root firmus.
Related word forms
How confirm is actually used
Standard in both formal and everyday registers. In formal contexts (legal, diplomatic), "confirm" often implies official ratification rather than simple verification. It takes a direct object and is frequently used with clauses introduced by "that."
Easily confused with confirm
"Confirm" means to establish that something already believed is true or to ratify it formally; "affirm" means to assert or state positively, often without prior doubt.