Its just an armless dream
It could mean a couple of things...
The symbol for left arm has been known to mean "nurturing, supportive"
The fact that it was 'Missing' means the lack thereof of the symbol.
The missing arm was not yours but of a girlfriend.
1) The dream could mean that you presently feel insecure about not having a girlfriend, lacking the support and nurturing a girlfriend would bring into your life.
2) The dream could mean that you've been attracted to girls who aren't very supportive or nurturing to you and that you need to find a girl who is.
3) The dream may mean that you seem to be attracted to the type of girl who is dependent missing on you.
Do either one of these interpretations make sense to you?
If not, I would need more details about your dream content, any other detail that you may have not noted . Write down each symbol and what you think the symbol may mean. Also I need to know how you were feeling in the dream, your mood? If you don't know what your mood was, take out a piece of paper and write down each symbol of the dream and the emotions you feel when thinking about the dream.
This may give you another clue to it's meaning.
It means you worry too much.
To me it means pass few days a female close to you it could be your mum asking you to do something which she is not able to do... nothing to worry about.. cheers from Singapore.
it means your gonna have a girlfriend with one arm , to be honest with you I really don't know :)