granum

As a noun granum

is (biology) a stacklike structure in plant chloroplasts that contain chlorophyll; the site of photosynthesis.

As a proper noun stroma is

an island of the northern coast of scotland.

In biology terms the difference between thylakoid and granum

is that thylakoid is a folded membrane within plant chloroplasts from which grana are made, used in photosynthesis while granum is a stacklike structure in plant chloroplasts that contain chlorophyll; the site of photosynthesis.

As a noun granum

is (biology) a stacklike structure in plant chloroplasts that contain chlorophyll; the site of photosynthesis.

As a verb grana is

to become gray or grayer.