Nouncentre; center; pivot; mainstay; nucleus; hub; backbone; central figure; pillar; key person · central nervous system

Na-adjective (keiyodoshi), Noun which may take the genitive case particle 'no', Noun(most) important; principal; pivotal; key; cardinal

Nounpivot hinge (using extensions on the top and bottom of a door that fit into cavities in the frame) · sliding wooden bolt (for holding a door or window shut)

Nouncavities in the frame of a door used as part of a pivot hinge · door

Nounextensions on the top and bottom of a door that fit into cavities in the frame (as part of a pivot hinge)