sub-(word root) under, below, beneathExamples of words with the root sub-: subject, subvert, subordinate, subcommitteeAbused, Confused, & Misused Words by Mary Embree Copyright © 2007, 2013 by Mary Embreesub-pref.1. Below; under; beneath: subsoil.2. a. Subordinate; secondary: subplot.b. Subdivision: subregion.3. Less than completely or normally; nearly; almost: subhuman.[Middle English, from Latin, from sub, under; see upo in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.sub- prefix 1. situated under or beneath: subterranean. 2. secondary in rank; subordinate: subeditor. 3. falling short of; less than or imperfectly: subarctic; subhuman. 4. forming a subdivision or subordinate part of a whole: subcommittee. 5. (Chemistry) (in chemistry)a. indicating that a compound contains a relatively small proportion of a specified element: suboxide. b. indicating that a salt is basic salt: subacetate. [from Latin sub]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014sub (s?b) n., v. subbed, sub?bing. n. 1. a submarine. 2. a substitute. 3. a submarine sandwich. 4. a sublieutenant. 5. a subordinate. 6. a subaltern. v.i. 7. to act as a substitute for another. [1695?1705; by shortening of words prefixed with sub-] sub- 1. a prefix, occurring orig. in loanwords from Latin, with the meanings ?under,? ?below,? ?beneath? (subsoil; subway), ?just outside of,? ?near? (subalpine; subtropical), ?less than,? ?not quite? (subhuman; suboscine; subteen), ?secondary,? ?at a lower point in a hierarchy? (subcommittee; subplot). 2. a. a prefix used in the names of chemical compounds that are bases. b. a prefix used in the names of compounds in which an element is present in a relatively small proportion: suboxide. For variants before following consonants in Latin loanwords, see su-, suc-, suf-, sug-, sum-, sup-, sur-2, sus-.[