Stool dream meaning is explained below using 5 different sources. Each interpretation is shown with its source.

Interpretation 1 — Martha Clarke

Given its usefulness (as much to sit down as to raise yourself to higher places) despite its small size, this dream announces that you will receive some help that will be very beneficial to you. 
Source: The Big Dictionary of Dreams Author: Martha Clarke

Interpretation 2 — Klaus Vollmar

Elevation, as in podium, but also unsafe seat. You need more security, support, and grounding.

Folklore: To sit on a stool is sitting in a place of honor.

Source: Little Giant Encyclopedia Author: Klaus Vollmar

Interpretation 3 — myjellybean

To dream of a stool suggests that you don’t feel completely comfortable about speaking your mind honestly. Have more faith in yourself.
Source: My Dream Interpretation Author: myjellybean

Interpretation 4 — Internet Archive - Anonymous

To dream of sitting on a Stool means honour and achievement through your own merits.
Source: Mystic Dream Book Author: Internet Archive - Anonymous

Interpretation 5 — Margaret Hamilton

A temporary seat, leaving one vulnerable, if backless
Source: Dream Dictionary Unlimited Author: Margaret Hamilton