What is the meaning of Gren?

Obsolete spelling of grin.

eggs (of silk worm)

a branch, bough

a branch

Alternative form of green

a branch

a branch (on a tree or bush)

a branch (part that splits off like a branch, concretely or abstractly)

a branch (line of family descent)

a branch (subdivision)

an event, a discipline

an event (one of several contests that combine to make up a competition – only put separately from the sense above since "discipline" sounds off here)

a crotch (area where the legs split from the torso, or the corresponding area on clothing)

grain (British English: corn)

Source: wiktionary.org