工学 航空电子系统确认及验证 释 line replaceable unit; LRU 外场可更换单元 从结构、功能或电气上，把飞行器零部件、系统或设备划分成若干在外场级维修中可以拆卸或更换的独立单元。
计算机体系结构 存储系统 释文 least recently used, LRU 最近最少使用
- oblong exit slit
- oblong number
- Obo
- Obock
- oboe
- Obolon' crater
- O. Bolza
- O. Bolza (1857—1942)
- Obo National Park
- Obregón, Ciudad
- Obruchev crater
- obscene publication
- obscuration
- obscure
- obscured homalomena rhizome
- obscured variable
- obscure gastrointestinal bleeding
- obscure puffer
- obscure pufferfish
- obscuring nebula
- obscuring torus
- obscurity
- observability
- observability canonical form
- observability index