Definitions

1. verb

to make something smooth and even; to remove rough or uneven parts from something

“The carpenter tried to smoothen the surface of the wooden table.”

2. verb (transitive)

to make someone or something feel more calm and less anxious

“The counselor tried to smoothen her client’s nerves before the big presentation.”

3. verb (intransitive)

to become or grow smoother

“The road will smoothen out as the winter snow melts.”