Homily

A homily is a commentary that follows a reading of scripture. In Catholic, Anglican, Lutheran, and Eastern Orthodox Churches, a homily is usually given during Mass (Divine Liturgy for Orthodox and Eastern Catholic Churches, and Divine Service for the Lutheran Church) at the end of the Liturgy of the Word. Many people consider it synonymous with a sermon.

Etymology

According to The Catholic Encyclopedia:

Roman Catholic Mass homily

The General Instruction of the Roman Missal (GIRM)

Other senses

Contemporary Protestant clergy often use the term 'homily' to describe a short sermon, such as one created for a wedding or funeral.

In colloquial usage, homily often means a sermon concerning a practical matter, a moralizing lecture or admonition, or an inspirational saying or platitude.