Word Unit: opistho-, opisth- (Greek: backward; behind, at the back, after, posterior)
Word Unit: opo-, op- + (Greek: juice)
Word Unit: opprobri- (Latin: scorn, disgraceful; shameful conduct, insulting, disrespectful, contemptuous remarks)
Word Unit: opsi-, ops- (Greek: late, later)
Word Unit: opsono-, opson-, opso-; opsino-; opsoni; -opsony + (Greek: boiled meat; to buy food; to purchase provisions; shopping)
Word Unit: optim- (Latin: the best, most favorable, most desirable; exceptionally good)
Word Unit: opulen- (Latin: wealth, wealthy, rich [power, might; abundance, plenty])

Inter-related cross references, directly or indirectly, involving word units meaning "more, plentiful, fullness, excessive, over flowing": copi-; exuber-; hyper-; multi-; ple-; pleio-; plethor-; poly-; super-; total-; ultra-; undu-.

Word Unit: -or; -our (primarily British) (Latin: a suffix; state of, result of; he who, that which)
Word Unit: ora-, or-, orat-; os- + (Latin: oris, mouth, face; opening, entrance; talk, speak, say)
Cross references of word families related directly, or indirectly, to: "talk, speak, speech; words, language; tongue, etc.": cit-; clam-; dic-; fa-; -farious; glosso-; glotto-; lalo-; linguo-; locu-; logo-; loqu-; mythico-; -ology; -phasia; -phemia; phon-; phras-; Quotes: Language,Part 1; Quotes: Language, Part 2; Quotes: Language, Part 3; serm-; tongue; voc-.

A cross reference of other word family units that are related directly, indirectly, or partially with: "opening, hole, cavity, tract, tube": alveolo-; antro-; anu-; celo-; coelio-; concho-; fenestra-; hernio-; hiat-; meato-; parieto-; poro-; pyl-, pyle-; pylor-; sphinctero-; splanchn-; stomato-; syringo-; uretero-; urethro-; vagino-; ventricul-.

Word Unit: -orama, -oramic, -rama (Greek: used as a suffix; view; sight; see, that which is seen)

Cross references of word families that are related directly, or indirectly, to: "appear, visible, visual, manifest, show, see, reveal, look": blep-; delo-; demonstra-; opt-; pare-; phanero-; phant-; pheno-; scopo-; spec-; vela-, veal-; video-, visuo-.

Word Unit: orb-, orbito- (Latin: rut or track made in the ground by a wheel; circle, ring, round surface, disk)
Word Unit: orc-, orca- (Greek > Latin: a kind of whale; large sea creature)
Word Unit: orches- (Greek: dance, pertaining to dancing)
Word Unit: orchido-, orchid-, orchio-, orchi-, -orchium (Greek > Latin: testes; testicles)
Word Unit: ord-, ordinato-, -ordin-, -ordinate, -ordinating, -ordinated (Latin: order, in order; in a row, regular series, class, rank)
Word Unit: orexi-, orex-, -orexia, -orexic, -oretic, -orectic, -rexia + (Greek: appetite [hunger]; to stretch out for; to desire)
Word Unit: orgado-, orgad- (Greek: open woodland, meadow, field)
Word Unit: organo-, organ- (Greek: an organized structure; pertaining to a specific bodily part with a specific function or set of functions; instrument, tool, implement)
Word Unit: orgasm, orgasms, orgasmic, orgastic + (Greek > Latin > French: excitement or violent action in an organ or part)
Word Unit: orgy, orgies (Greek > Latin orgia (pl), secret rites)

A cross reference of other word family units that are related directly, or indirectly, to: "secret, hidden, confidential, concealed": ceal-; clandesti-; crypto-; myster-; occult-; stego-, stegano-.