span vs pier

span and pier both are nouns.

Word	Noun	Adjective	Verb	Adverb
span	Yes	No	Yes	No
pier	Yes	No	No	No

span (noun)	pier (noun)
the act of sitting or standing astride	a platform built out from the shore into the water and supported by piles; provides access to ships and boats
a structure that allows people or vehicles to cross an obstacle such as a river or canal or railway etc.	a support for two adjacent bridge spans
the distance or interval between two points	(architecture) a vertical supporting structure (as a portion of wall between two doors or windows)
a unit of length based on the width of the expanded human hand (usually taken as 9 inches)
two items of the same kind
the complete duration of something

span (verb)	pier (verb)
to cover or extend over an area or time period