1.
If you describe something as ~, you mean that it is less important than something else.
The street erupted in a huge explosion, with ~ explosions in the adjoining buildings...
The actual damage to the brain cells is ~ to the damage caused to the blood supply.
ADJ: usu ADJ n, also v-link ADJ to n
2.
Secondary diseases or infections happen as a result of another disease or infection that has already happened.
He had kidney cancer, with ~ tumours in the brain and lungs.
ADJ: usu ADJ n
3.
Secondary education is given to pupils between the ages of 11 or 12 and 17 or 18.
Examinations for the GCSE are taken after about five years of ~ education.
ADJ