Charles Buck Theological Dictionary 
The plural noun has various significations; as the general way of life, the morals or the habits of any person; also ceremonial behaviour or studied civility. Good manners, according to Swift, is the art of making those people easy with whom we converse. Pride, ill-nature, and want of sense, are the three great sources of ill-manners. Without some one of these defects no man will behave himself ill for want of experience; or of what, in the language of some, is called knowing the world. For the effect that Christianity has on the manners of men, see article CHRISTIANITY.
King James Dictionary 
MAN'NERS, n. plu. Deportment carriage behavior conduct course of life in a moral sense.
Evil communications corrupt good manners. 1 Corinthians 15
1. Ceremonious behavior civility decent and respectful deportment.
Shall we, in our applications to the great God, take that to be religion, which the common reason of mankind will not allow to be manners?
2. A bow or courtesy as, make your manners a popular use of the word.