spire

Concise Oxford English Dictionary © 2008 Oxford University Press:
spire1

▶noun

• 1 a tapering conical or pyramidal structure on the top of a building, typically a church tower.

• 2 the continuation of a tree trunk above the point where branching begins.

– derivatives
spired adjective,
spiry adjective.

– origin OE spīr ‘tall slender stem of a plant’.

Concise Oxford English Dictionary © 2008 Oxford University Press:
spire2

▶noun Zoology the upper tapering part of the spiral shell of a gastropod mollusc.

– origin C16: from Fr., or via L. from Gk speira ‘a coil’.