Mark is a laid back person.
Mark is a lay back person.
i mean them to describe someone who is not proactive and who doesn't care enough, in a critical sense.
I googled both terms and the numbers of result of are both large. So, conventionally, are both terms acceptable in most contexts? Or do they basically mean different things in itself?
By the way, when I say a "large" number of results, I'm talking about millions of hits for lay back person.