To dream of being on a slide, signifies that you are suffering from the unstable life. You have lost the balance you had before, therefore you feel like there is no strong ground under your feet.
Dream dictionary: Slide dream meanings
To see a slide in dreams signifies the fact that you will be facing the hardships while managing your affairs or businesses. This situation will require the mastery while dealing with yourself and the desire to work while making the right decisions in order to succeed.
Some business matters will not go according to plan.
(see SKATE)
This dream shows insecurity, fear and anxiety. It warns us that we have entered a new slippery ground that can take us down. (Also look at the meaning of To fall)
…Dreaming of sliding, portends disappointments in affairs, and sweethearts will break vows. To slide down a hillside covered with green grass, foretells that you will be deceived into ruin by flattering promises….