sub-

a prefix occurring originally in loanwords from Latin (subject; subtract; subvert; subsidy); on this model, freely attached to elements of any origin and used with the meaning “under,” “below,” “beneath” (subalpine; substratum), “slightly,” “imperfectly,” “nearly” (subcolumnar; subtropical), “secondary,” “subordinate” (subcommittee; subplot).

Chemistry.

a prefix indicating a basic compound:
subacetate; subcarbonate; subnitrate.
a prefix indicating that the element is present in a relatively small proportion, i.e., in a low oxidation state:
subchloride; suboxide.

Also, su-, suc-, suf-, sug-, sum-, sup-, sur-, sus-.

Origin

< Latin, combining form representing sub (preposition); akin to Greek hypó; see hypo-

British Dictionary definitions for sub-

sub-

prefix

situated under or beneath: subterranean

secondary in rank; subordinate: subeditor

falling short of; less than or imperfectly: subarctic, subhuman

forming a subdivision or subordinate part of a whole: subcommittee

(in chemistry)

indicating that a compound contains a relatively small proportion of a specified element: suboxide
indicating that a salt is basic salt: subacetate

Word Origin

from Latin sub

Word Origin and History for sub-

word-forming element meaning "under," from Latin preposition sub "under" (also "close to, up to, towards"), from a variant form (*(s)up-, perhaps representing *ex-upo-) of PIE root *upo- "from below," hence "turning upward, upward, up, up from under, over, beyond" (cf. Sanskrit upa "near, under, up to, on," Greek hypo "under," Gothic iup, Old Norse, Old English upp "up, upward," Hittite up-zi "rises"). Used as a prefix and in various combinations.

The original meaning is now obscured in many words from Latin ( suggest, suspect, subject, etc.). The prefix is active in Modern English, sometimes meaning "subordinate" (as in subcontinent, first recorded 1863) or "inferior" (a sense first attested 1963).

sub- in Medicine

sub- pref.

Below; under; beneath: subcutaneous.
Subordinate; secondary: subinfection.
Subdivision: subkingdom.
Less than completely or normally; nearly; almost: subfertility.

sub- in Science

sub-
A prefix that means "underneath or lower" (as in subsoil), "a subordinate or secondary part of something else" (as in subphylum.), or "less than completely" (as in subtropical.)