IPA: /ˌsɛntəˈmɛn.təl.ɪ.zəm/
KK: /sɛntəˈmɛntəlɪzəm/
A tendency to have strong feelings or emotions, often in an exaggerated way, especially in art or literature.
Her sentimentalism was evident in the way she wrote about her childhood memories.
Sentimentalism is formed from "sentiment" (from French *sentiment*, meaning feeling or emotion) and "-al" (meaning pertaining to) and "-ism" (meaning a practice or philosophy). The word refers to a philosophy or practice that emphasizes feelings and emotions.
Think of 'sentiment' as relating to feelings, and remember that 'sentimentalism' is about a philosophy that focuses on emotions.