IPA: /ˌaɪdiˈɒlədʒi/
KK: /aɪˈdiːəˌlədʒi/
A collection of ideas and beliefs that shape the way a group or individual thinks about politics, society, or culture.
Her ideology influenced her decisions in the political arena.
Ideology is formed from "ideo-" (from Greek "idea", meaning form or concept) and "-logy" (from Greek "logia", meaning study or discourse). The word refers to the study or discourse of ideas and concepts, particularly in a political or social context.
Think of 'ideas' ('ideo-') being studied or discussed ('-logy') — that's what ideology means.