1 : a pipe used to transport liquids or gases; "a pipeline runs from the wells to the seaport"
2 : mechanical system in a factory whereby an article is conveyed through sites at which successive operations are performed on it
3 : a telephone connection
4 : a particular kind of product or merchandise
5 : a conductor for transmitting electrical or optical signals or electric power
6 : a connected series of events or actions or developments
7 : (often plural) a means of communication or access
8 : the principal activity in your life that you do to earn money
9 : a succession of notes forming a distinctive sequence
10 : a slight depression in the smoothness of a surface
1 : be in line with; form a line along