Use waver for hesitating, showing doubt, or swaying unsteadily, as in "his voice wavered" or "the flame wavered in the draft". Use waiver for the document that gives up a legal right or claim, as in "he signed a waiver before bungee jumping". A memory hook: waiver has an i, like a legal document you sign.
The core difference
Waver is the verb for hesitating or swaying; waiver is the noun for a document giving up a right.
- waver — verb, to hesitate or show doubt: Her support for the plan never wavered, even under pressure.
- waver — verb, to sway or move unsteadily: The flame wavered in the draft from the open door.
- waiver — noun, a document giving up a legal right: The gym requires a medical waiver for anyone over 65.
How to tell them apart
Waver comes from an old word meaning "to wave", sharing its root with wave itself — which fits both senses: swaying like something caught in the wind, and wavering between two decisions. Waiver is a different word entirely, built from the verb waive plus the -er ending, and first recorded in the 1600s as a term for giving something up.
The two get mixed up mostly in writing about forms and consent, where someone means the signed document but types "waver" instead. Since waiver always refers to a physical or formal document, checking whether the word is naming a thing you sign is the fastest way to catch the error.
