Blow Pipe/Gun
Like any weapon in a dream, it represents the capability of hurting someone or being hurt or even killed (emotionally). But the particular associations are probably to do with things people have said which have got under your skin, perhaps without your awareness. The words probably have malice/poison in them which works away in your mind and feelings creating a sense of unrest or even irrational depression. These feelings are all the harder to deal with because we are not aware of their entrance into us. When we discover the dart however, this usually clears the influence – the dart being the words or hidden intentions behind the poisonous words or emotions.
If you are blowing the dart: Have you maliciously said something or done something to someone? See: weapons.
Useful Questions and Hints:
Have I felt depressed or strange after being with someone?
Is there something that happened or was said that has upset me or left a strange feeling?
Who am I aware of who is trying to ‘get at’ me?
See Victims and also Easy Dream Interpretation