What is the meaning of ?

key, important point

essential piece of something, requirement

a pin or rivet holding the spines of a folding fan together

a pivot, cornerstone, keystone

a pin, often decorated, holding the handle to the tang of a katana

short for 要黐 (kaname mochi): a tree, Japanese photinia (Photinia glabra)

in a certain kind of traditional Japanese hip roof where the rafters splay out like the spines of a fan, the central point to which the rafter lines converge

a unisex given name

the pin or rivet holding the spines of a folding fan together

fortress, redoubt

important point, key

Source: wiktionary.org