late 15c., "play or sing in harmony," from French harmoniser (15c.), from Old French harmonie (see harmony). Meaning "be in harmony (with), go well together" is from 1620s. Transitive sense "bring into harmony" is from 1700; figurative sense "bring into agreement" is from 1767. Meaning "add harmony to (a melody)" is from 1790. Related: Harmonized; harmonizing.
1. The new building does not harmonize with its surroundings.
2. Bremer and Garland harmonize on the title song, "Meet Me in St. Louis".
3. Barbara White and her mother like to listen to music together, though their tastes don't harmonize.
4. The colours do not seem to harmonize with each other at all.
5. It would be sensible if we could harmonize our plans ( with yours ).