1. At the start of a sentence may indicate thinking before answering.
Often the user is trying find thew right words to gently say no. It also prepares the listener for a dubious/skeptical/negative response.
2. on it's own - depends on pronunciation - means whatever you want it to.
3. end of sentence - the person has kept talking after they have anything to say
1.
q - what do you think of my painting a - meh, I prefer sculpture
A synonym for "Me" invented by the same annoying idiots that invented LOL, XD, OMG, and countless others.
this is one word in a language used by those annoying idiots to sound cute.