;Disconnection: A retrosynthetic step involving the breaking of a bond to form two (or more) synthons.
;Retron: A minimal molecular substructure that enables certain transformations.
;Retrosynthetic tree: A directed acyclic graph of several (or all) possible retrosyntheses of a single target.
;Synthon: A fragment of a compound that assists in the formation of a synthesis, derived from that target molecule. A synthon and the corresponding commercially available synthetic equivalent are shown below:
;Target: The desired final compound.
;Transform: The reverse of a synthetic reaction; the formation of starting materials from a single product.