According to Webster's...
by Ivayla (guest)
1/22/2004, 5:10 PM
manner
n.
...
3.[pl.]
a) ways of social life; prevailing social conditions or customs (a comedy of manners)
b) ways of social behavior; deportment, esp. with reference to polite conventions (good manners, bad manners)
c) polite ways of social behavior; deportment conforming with polite conventions (a child who has no manners)
I am guessing that is the definition you wanted