IPA: /ˌreɪʃiəʊsɪˈneɪʃən/
KK: /ˌreɪʃiəˈsɪneɪʃən/
The process of thinking carefully and logically to form conclusions or judgments.
Her ratiocination led her to solve the complex problem efficiently.
Ratiocination → It is formed from "ratio" (from Latin, meaning reason or calculation) and "-cination" (derived from the Latin suffix "-cinare", meaning to act or process). The word refers to the process of reasoning or logical thinking.
Think of 'reason' ('ratio') and the act of 'processing' ('-cination') to remember that ratiocination means the process of reasoning.