means The tapering, pointed top of a tower or steeple that rises to a sharp peak, especially on a church.

from From Old English 'spir,' meaning a stalk, sprout, or blade of grass — the slender shoot a plant sends skyward. The word kept that sense of something tall and tapering as it climbed onto architecture, and it's related to a cluster of Germanic words for spikes and shoots, a cousin of 'spear' in spirit if not strict descent.