action：行动，行为；活动，动作；作用，生效

词根词缀： -act-行动 + -ion名词词尾

• obtrude
• obtrusive
• obtund
• obtuse
• obtuse angle
• obverse
• obviate
• obvious
• obviously
• oc-
• ocarina
• occasion
• occasional
• occasionality
• occident
• occidental
• occidentalism
• occidentalist
• occlude
• occult
• occultist
• occupancy
• occupant
• switchblade
• switchboard