To shout - yell via e-mail, text message, etc... by WRITING WITH ALL CAPITAL LETTERS TO MAKE A POINT instead of using asterisks and underscored words which are considered a gentler way to emphasize something.
a) Happy and Smiling, like a yelley happy face.
b) Scared, like someone who is yella'...
c) Loudy, like a people who keeps on yelling.
d) Melonin deprived, like a person who is very yelley...