gablet

As nouns the difference between canopy and gablet

is that canopy is a high cover providing shelter, such as a cloth supported above an object, particularly over a bed while gablet is (architecture) a small gable, or gable-shaped canopy, formed over a tabernacle, niche, etc.

As a verb canopy

is to cover with or as if with a canopy.

In architecture terms the difference between gable and gablet

is that gable is the triangular area of external wall adjacent to two meeting sloped roofs while gablet is a small gable, or gable-shaped canopy, formed over a tabernacle, niche, etc.