| 序号 | 英文 | 音标 | 词性 | 中文 |
| | opposite crank | | | 对置曲柄 |
| | opposite direction | | | 反向, 敌对[相反]方向 |
| | opposite direction pulse | | | 反向脉冲 |
| | opposite edge of a polyhedron | | | 多面 体的对棱 |
| | opposite experiment | | | 对比实验 |
| | opposite forces | | | 对向力 |
| | opposite joint | | | 对接接头, (齐)平接头 |
| | opposite leaf | | | 对生叶 |
| | opposite leg | | | 异名腿 |
| | opposite number | | n. | 对应的人，对应的物 |
| | opposite parity | | | 相反奇偶性 |
| | opposite phase | | | 反相 |
| | opposite pitting | | | 对列纹孔式 |
| | opposite pole | | | 异性极 |
| | opposite projective | | | 反向射影 |
| | opposite routes | | | 对向进路, 敌对进路 |
| | opposite sense | | | 反指向 |
| | opposite sequence | | | 逆顺序 |
| | opposite sex | | | 异性 |
| | opposite side | | | 对边 |
| | opposite sign | | | 异号, 反号 |
| | opposite spin | | | 反向自旋, 反方向旋转 |
| | opposite typeregion | | | 相反型区域 |
| | opposite vertex | | | 对顶 |
| | opposite viewpoint | | | 换质位, 换质位法 |
| | oppositely | | adv. | 相对地, 对立地 |
| | oppositely directed photons | | | 反方向传播的光子 |
| | oppositely equal pencils | | | 反向等线束 |
| | oppositetransition | | | 反向跃迁 |
| | opposition | CpE5ziFEn | n. | 反对, 敌对, 相反, 反对派, [天]冲, [逻]对当法 |
| | opposition duplex | | | 反双工 |
| | opposition of propositions | | | 命题的对立关系 |
| | opposition parry | | | 对抗防守 |
| | oppositional | 9CpE`zIFLnEl | adj. | 反对的,对抗的 |
| | oppositionist | 9CpE`zIFLnIst | n. | 反对党人,反对派成员 |
| | oppositive | E5pCzEtiv | | 表示反对的 |
| | oppress | E5pres | vt. | 压迫, 压抑 |
| | oppression | E5preFEn | n. | 压迫, 镇压, 压抑, 苦恼 |
| | oppressive | E5presIv | adj. | 压制性的, 压迫的, 沉重的, 难以忍受的 |
| | oppressive agreement | | | 苛刻的协议 |
| | oppressive clause | | | 苛刻的条款 |
| | oppressive practices | | | 压迫行为 |
| | oppressive weather | | | 闷热天气 |
| | oppressively | | adv. | 压迫地, 沉重地 |
| | oppressor | E`presE(r) | n. | 压迫者 |
| | opprobrious | E5prEubriEs | adj. | 嘴不干净的, 无礼的, 粗野的, 该骂的, 可耻的 |
| | opprobrium | E5prEubriEm | n. | 不名誉, 耻辱, 责骂 |
| | oppugn | E5pju:n | vt. | 责难, 反驳, 质疑, 抗击 |
| | oppugnant | E5pQgnEnt | adj. | <罕>反对的,敌对的 |
| | oppugner | | | 抗击者 |
| | opressive | E5presiv | | 暴虐的 |
| | opsearch | 7Cp5sE:tF | | 运筹学 |
| | opsimath | 5CpsimAW | n. | 晚年开始学习的人 |
| | opsimathy | Cp5simEWi | | 接受教育晚 |
| | opsin | 5Cpsin | n. | [生化]视蛋白 |
| | opsogen | 5CpsEudVEn | | 调理素原 |
| | opsone | 5CpsEun | | (细菌)调理素 |
| | opsonic | Cp5sCnik | adj. | [微]调理素的 |
| | opsonic index | | n. | 噬菌指数, 调理指数 |
| | opsonic reaction | | | 调理素反应 |
| | opsonification | Cp7sCnifi5keiFEn | | 调理素作用 |
| | opsonigenous substances | | | 细菌代谢产物 |
| | opsonin | 5CpsEnin | n. | [微]调理素 |
| | opsonize | 5CpsEnaiz | | [生化]使(细菌)易受调理素的作用,调理作用 |
| | opster | `CpstE(r) | n. | <美口>光效应艺术家,视幻艺术家 |
| | opt | Cpt | vi. | 选择 |
| | opt for | | v. | 选择 |
| | opt in | | | 决定参加 |
| | optacon | 5CptEkCn | | 盲人阅读器 |
| | optant | | | 选择者 |
| | optate | 5Cpteit | vi. | 选择,作出抉择 |
| | optative | 5CptEtiv | adj.；n. | adj. 祈愿的；n. [语]祈愿语态, 祈愿语态的动词 |
| | optative mood | | | 祈愿语气 |
| | optative sentence | | | 愿望句 |
| | optic | 5Cptik | adj. | 眼的, 视觉的, 光学上的 |
| | optic angle | | | 光(轴)角 |
| | optic atrophy | | | 视神经萎缩 |
| | optic block | | | 光学系统, 光学装置 |
| | optic capsule | | | 视囊 |
| | optic centre | | | 视觉中心 |
| | optic chiasma | | | 视交叉 |
| | optic cup | | | [解]视杯 |
| | optic gland | | | [动](无脊椎)视腺 |
| | optic lobe | | | 视(神经)叶 |
| | optic nerve | | n. | 视神经 |
| | optic nerve fibre | | | 视神经纤维 |
| | optic plate | | | 视基板 |
| | optic radiation | | | 视辐(射)线 |
| | optic rudiment | | | 视原基 |
| | optic segment | | | 视神经节 |
| | optic sign | | | [矿]光性符号 |
| | optic tract | | | [解]视束 |
| | optic tubercle | | | (蝇幼虫)眼瘤 |
| | optic zone | | | 视带, 视区 |
| | optical | 5CptikEl | adj. | 眼的, 视力的, 光学的 |
| | optical aberration | | | 光学象差 |
| | optical absorption edge | | | 光学吸收限 |
| | optical accessary | | | 光学附件 |
| | optical acquisition | | | 光学探测 |
| | optical activity | | | [物]旋光性[度] |
| | optical address | | | 光寻址 |