reflexive.

transitive. To make free from worry or apprehension; to put at ease; (also) to make careless or overconfident. Obsolete.

transferred or figurative. To render sleek or smooth, in various senses. Denoting removal of agitation, disturbance, deep thought, etc.

(un-, prefix2 affix 1d(c).)

(un-, prefix2 affix 1b(b).)

transitive. To free from concern or anxiety.

(un-, prefix2 affix 1d(c).)

To make (a person, his mind, etc.) calm and tranquil. †Also, to render free from (anything that perturbs).