arbor

Multiple Entries:
  arbor    arbour  

Concise Oxford English Dictionary © 2008 Oxford University Press:
arbor1 /ˈɑːbə/

▶noun

• 1 an axle on which something revolves.

• 2 a device holding a tool in a lathe.

– origin C17: from Fr. arbre ‘tree, axis’, influenced by L. arbor ‘tree’.

Concise Oxford English Dictionary © 2008 Oxford University Press:
arbor2

▶noun US spelling of arbour.

Concise Oxford English Dictionary © 2008 Oxford University Press:
arbour /ˈɑːbə/ (US arbor)

▶noun a garden alcove with the sides and roof formed by trees or climbing plants.

– derivatives
arboured adjective.

– origin ME: from OFr. erbier, from erbe ‘grass, herb’, from L. herba; influenced by L. arbor ‘tree’.