a Lawn could be simply a a random caracter running around shouting ''WTF DO I GO!?'' or someone calling someone else a Lawn and then getting mowed.
A lawn is an idiot and he doesnt know it infact the only ones who dont know what lawns are, are lawns.
Lawn implies that you are inexperienced
sometimes it is used as slang for 'you suck' or "you are not very good at a game"
Im gonna MwP that lawn hard.
Someone kick that lawn hes useless.
Man these lawns are driving me crazy!!!