---

• outset
• origin
• Oz
• OS
• onus
• obsession
• occlusion
• offensive
• overrule
• outlaw
• overdue
• orchard
• outperform
• original
• outermost
• orchestra
• ownership
• orphanage
• overshoot
• outskirts
• operation
• opportune
• orientate
• oligarchy
• originate
• officious
• overnight
• obscenity
• otherwise
• overwhelm
• overall
• outline
• occupy
• output
• obtain
• officer
• operate
• obvious
• obey
• ought
• ocean
• omit
• ours
• oh
• omega
• objection
• opus
• oral
• onto
• outer
• opera
• objective
• obscure
• owe
• opinion
• odd
• opportunity
• obnoxious
• overpower
• oxidation
• offense
• outcrop
• overlay
• operand
• outflow
• outlive
• ornate
• obelisk
• oomph
• oriel
• ogle
• ox
• occurrence
• occasional
• ostentatious
• obstetrics
• obligation
• ordination
• overweight
• obsolescent
• oscillation
• orchestrate
• occupant
• originality
• outstanding
• omnipresent
• oryx
• okra
• orca
• orbit
• optic
• overt
• odium
• outdated
• olfactory
• obtrusive
• obscurity
• observant
• obfuscate
• overboard
• orthodoxy
• outnumber
• overdraft
• operative
• owl
• ole
• oaf
• ort
• ooh
• ore
• orc
• oho
• ope
• oda
• optimization
• objectivity
• observatory
• outward
• other
• orchid

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因篇幅关系，字母O开头的单词只列出前 120 个；字母O开头的英语单词由翁笔典籍网提供查询