Allay (verb)

1. To make (a feeling or fear) less intense; to calm or pacify.
2. To reduce or remove (a concern or doubt).

Origin:

Middle english (in the sense "make less severe"): from old french alaier, from a- (from latin ad "to") + laier "to lessen".

Examples:

1. The news of her recovery allayed our fears for her safety.
2. The painkiller will allay the headache.
3. He allayed her concerns by assuring her that everything would be fine.
4. The explanation allayed my confusion about the topic.
5. He tried to allay the tension with a joke.