n.

1. 【语】连词 [C]
   "And", "but", and "while" are all conjunctions.

   “和”、“但是”以及“当……时候”都是连词。

2. 结合；关联；连接 [C][U]
   The cause of the accident is the conjunction of technical and managerial factors.

   事故的原因是技术因素和管理因素共同造成的。

3. 同时发生 [U]
4. 【天】合相，（天体的）会合（两星或星与基本点间成零度的视角）[U]

n.

1. Grammar  a word used to connect clauses or sentences or to coordinate words in the same clause (e.g. and, if).
2. an instance of two or more events occurring at the same point in time or space.
   ▸Astronomy  & Astrology  an alignment of two planets so that they appear to be in the same place in the sky.