As a noun subtree
is (mathematics|computer science) a tree wholly contained in another.
As an adjective postorder is
(computing theory) of a tree traversal, recursively visiting the left and right subtrees before the root.
subtree
English
Noun
(
en noun)
(mathematics, computer science) A tree wholly contained in another.
postorder
English
Adjective
(-)
(computing theory) Of a tree traversal, recursively visiting the left and right subtrees before the root.