IPA: /ɪˈstæblɪʃmənt/
KK: /ɪˈstæblɪʃmənt/
A group or organization that has control or influence in a particular area, or a place where people live or work, such as a business or institution.
The establishment of new schools in the area has improved education for many children.
Establishment is formed from "establish" (from Old French *establir*, meaning to make stable or firm) and "-ment" (a suffix used to form nouns indicating an action or resulting state). The word refers to the action or state of making something stable or firm, often in the context of institutions or organizations.
Think of 'making stable' ('establish') and the '-ment' indicating a state or action — that's why establishment refers to the state of having something firmly set up.