Definition of pier
1
: an intermediate support for the adjacent ends of two bridge spans
2
: a structure (such as a breakwater) extending into navigable water for use as a landing place or promenade or to protect or form a harbor
3
: a vertical structural support: such as
a
: the wall between two openings
c
: a vertical member that supports the end of an arch or lintel
d
: an auxiliary mass of masonry used to stiffen a wall
4
: a structural mount (as for a telescope) usually of stonework, concrete, or steel
