horizontal
adjective
uk/ˌhɒrɪˈzɒntəl/ ussomething that is horizontal goes across, level to the ground, rather than up or down:
Horizontal drilling has given the oil industry a way to extract oil from places where it was once almost impossible.
relating to companies, departments, etc. that have the same activities as each other:
a horizontal agreement/alliance
relating to a company or organization that has few or no different levels of management:
The horizontal organization allows participants to solve many problems themselves.
a horizontal management structure/system
Compare
vertical