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-.

Word Unit: oriri-, orir-, ori-, or- (Latin: to rise, arising, to be born, source, original; the rising sun, east; to ascend, to spring up, to become visible, to appear)
Word Unit: -orium, -oria, -ory (Latin: a suffix; a place or instrument for performing the action of the main element; a place used for something)
Word Unit: orn- (Latin: to equip; to prepare, to furnish, to fit out)
Word Unit: oro-, or-, ori- (Latin: mouth, face; referring to the "mouth")
Word Unit: oro-, oreo-, ore-, oreino-, orein- (Greek > Latin: mountain; hill)
Word Unit: oro-, orrho- (Greek: whey, serum)

Serum, whey words are also at this sero-, ser- unit.

Word Unit: -orrhexis, -rhexis, -rrhexis (Greek: used as a suffix; rupture of an organ or vessel; a breaking forth, bursting)
Word Unit: ortho-, orth- (Greek: right, straight, correct, true; designed to correct)
Word Unit: -ory (Latin: a suffix of adjectives ending in -ory; of or relating to; like; resembling)