Great big grin
Big Wide Grin was created in 2001.
The big grin emoticon is simply ":D" so it may mean he is happy. The Emoticons are used in almost every Yahoo Conversation so probably nothing.
Grin means to smile happily
Grin
A GRIN is a big smile.
His big grin told us that he liked the gift very much.
Grin from ear to ear means when your smile is really big because you are really happy.
Grin ;D
The future tense of "grin" is "will grin."
The term "mean long grin" is not commonly used or recognized. It is likely a made-up phrase or a specific term used in a certain context or community. Without further information, it is difficult to provide a specific meaning for this phrase.
Yes: grins is the plural of grin.