When you have been remiss, you have been careless because you did not do something that you should have done.
A missive is a written letter, especially a formal, legal, or important one.
An emissary is someone who acts as a representative from one government or leader to another.
When something, such as a disease or storm, is in remission, its force is lessening or decreasing.
When someone is submissive, they are highly obedient or inclined to give in to the demands of others.
When you dismiss someone, you send them away.
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