sub- prefix1 : under
: below [sub standard]
2 a : subordinate
: next lower than or inferior to [sub agent]
b : subordinate portion of
: subdivision of [sub chapter] [sub committee]
c : assigning to another by the same method [sub license] [sub contract]
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.