IPA: /ˌsɛntɪˈmɛntəli/
KK: /sɛntəˈmɛntəli/
In a way that shows strong feelings of love, sadness, or nostalgia.
She looked at the old photographs sentimentally, remembering the happy times they represented.
Sentimentally → It is formed from "sentiment" (from Latin "sentimentum", meaning feeling or thought) and "-ally" (meaning in a manner relating to). The word "sentimentally" means in a manner that relates to feelings or emotions.
Think of 'sentiment' as relating to feelings, and remember that 'sentimentally' describes doing something in a way that expresses those feelings.