To enlist (someone) or make (someone) a member of
To enlist oneself (in something) or become a member (of something)
To enter (a name, etc.) in a register, roll or list
To write or cut (words) onto (something, especially a hard surface, or a book to be given to another person); to engrave.
To draw a circle, sphere, etc. inside a polygon, polyhedron, etc. and tangent to all its sides.