Noun
The irregular triangular space between the curve of an arch and the inclosing right angle; or the space between the outer moldings of two contiguous arches and a horizontal line above them, or another arch above and inclosing them.
A narrow mat or passe partout for a picture.
Source: Webster's dictionaryThis bridge is also historically significant as it is the world's oldest open- spandrel stone segmental arch bridge. Source: Internet
In architecture, a spandrel is a curved area of masonry which exists between arches supporting a dome. Source: Internet
This process is able to adapt complex structures from simpler beginnings, or convert complex structures from one function to another (see spandrel ). Source: Internet