IPA: /ˌsuːpəˈstɪʃən/
KK: /ˌsuːpərˈstɪʃən/
A belief or practice that is based on fear, ignorance, or a misunderstanding of how things work, often involving magic or luck.
Many people avoid walking under ladders because of superstition.
Superstition is formed from "super-" (meaning above or over) and "stitio" (from "stare", meaning to stand). The word refers to beliefs that stand above or beyond rational understanding, often involving the supernatural.
Think of beliefs that stand 'above' ('super-') what is rational or scientifically proven, which helps you remember that 'superstition' refers to irrational beliefs.