Finial (noun)

A decorative ornament that finishes or tops off a spire, gable, pinnacle, or other architectural feature.

Origin:

Late middle english from old french 'finiale' from latin 'finire' (to finish).

Examples:

1. The cathedral was crowned with a large golden finial.
2. The finials on the roof of the building were carved with intricate patterns.
3. The finial on the tip of the flagpole was made of brass.
4. The finials on the antique four-poster bed were hand-carved and beautifully detailed.
5. The finial served not only as a decorative element but also as a functional lightning rod.