Europe (abbr. for 歐洲|欧洲[Ou1 zhou1]); European Union (abbr. for 歐盟|欧盟[Ou1 meng2]); surname Ou

ohm (abbr. for 歐姆|欧姆[ou1 mu3]); euro (abbr. for 歐元|欧元[ou1 yuan2]); used in transliteration; old variant of 謳|讴[ou1]

Owen (name); Erwin (name); Irvine, California

euro (currency)

European (person)

Leonhard Euler (1707–1783), Swiss mathematician

European Union; EU

two-character surname Ouyang

Owens (name)

(loanword) ohm

(coll.) okay (loanword from "over")

Europe and Asia; Eurasia

Eugene (name)

UEFA Champions League

euro cent

European-style bread; (esp.) sourdough bread (abbr. for 歐洲麵包|欧洲面包[Ou1 zhou1 mian4 bao1])

Opel (car brand)

(female usage) older sister (loanword from Korean "eonni")

(female usage) older brother (loanword from Korean "oppa"); male friend

in the European style; Euclidean

medlar (Mespilus germanica)

common hazel (tree) (Corylus avellana)

Euclid; abbr. for 歐幾里得|欧几里得

(Internet slang) very good luck (esp. in games)

opal (Sanskrit: upala)

(ACG) breasts (loanword from Japanese "oppai")

(economics) (derog.) PIGS (Portugal, Italy, Greece and Spain); PIIGS (Portugal, Italy, Ireland, Greece and Spain)

Europe and America; the West

parsley (Petroselinum sativum)

(loanword) au lait; with milk

continental Europe

(bird species of China) stock dove (Columba oenas)

(loanword) oh my God!

(bird species of China) European robin (Erithacus rubecula)

OPEC; Organization of the Petroleum Exporting Countries

Eurozone

abbr. for 歐洲共同體|欧洲共同体, European Community (old term for the EU, European Union)

older man; man of mature years (Japanese loanword)

(bird species of China) European nightjar (Caprimulgus europaeus)

(Tw) omelette

Omron Corporation (Japanese electronics company)

older female; woman of mature years (Japanese loanword)

(Tw) Barack Obama (1961–), US Democrat politician, president 2009–2017

(botany) lovage; Levisticum officinale

(bird species of China) European turtle dove (Streptopelia turtur)

Oberlin

(bird species of China) willow warbler (Phylloscopus trochilus)

(bird species of China) song thrush (Turdus philomelos)

European Cup (e.g. soccer)