The phrase “tertiary” is an adjective which means “of third significance or rank”. It’s usually used to explain one thing that’s much less vital than two different issues. For instance, you may say that your “tertiary” purpose is to learn to play the guitar. Which means that studying the guitar is much less vital to you than two different objectives, resembling ending faculty and getting a job.
The phrase “tertiary” can be used to explain one thing that’s third in a collection. For instance, you may say that the “tertiary” stage of a challenge is the testing section. Which means that the testing section is the third stage of the challenge, after the planning and growth levels.