To dream of armpits represents thoughts and feeling associated with social acceptance and approval. Armpits may also reflect feelings about cultural attitudes or corporate culture. Feelings about what is or isn't acceptance by people you spend a lot of time around.
Negatively, armpits in a dream may reflect behavior by you or someone else that is inappropriate. Disgusting true intentions being discovered.
Hairy armpits may reflect a more laid back attitude or appearing to others as though you don't care about what they think of your choices or behavior.
Shaven armpits may reflect a more careful or sensitive attitude towards social acceptable behavior. Not wanting to appear too laid back or comfortable with something others may not feel is socially acceptable.
Example: A woman dreamed of herself having long straggly armpit hair that she forgot to shave. In waking life someone jealous at her workplace was continually messing up her desk and making her look to her employers like she was comfortable being lazy and disorganized while other people weren't.
Example 2: A man dreamed of seeing someone getting an axe chopped in their armpit. In waking life he heard news about a criminal who attempted to rob his father's house being shot to death.