Traditional Meanings:

European (Judeo-Christian)

• Be aware if see waistcoat – Dreaming of west or waistcoat in general this may be that your are surrounded by hostility so you have to be attentive;
• Be attentive if wear waistcoat – The waistcoat in the dream which one you are wearing shows that you have to pay attention to your actions and hide suspicion.

Hindu (Hinduism)

• Think what you speak if wear vest – In your dream you wear vest then you have to  think more of what you say to the people in order not to insult;
• Improvement if see waistcoat (vest) – You are planning to make some improvements for yourself or your life.

* Please, see also meaning of jacket & clothing interpretation.