"Boomsday" has strong, wisecracking main characters, but its secondary ones are even better.

Does nature or culture destine women for primary roles at home and secondary ones in the work force?

Six main struts had to be checked out, and six secondary ones.

Researchers have found that delusions like this can be passed from primary patients to secondary ones, usually susceptible family members or close associates.

The main honjin was located in front of the shrine, with one of the secondary ones on each side.

Given the opportunity, I avoid busy roads and instead use secondary ones.

They were instruments too, but only secondary ones.

Here is a look at how the week developed in major markets and several key secondary ones.

I've been trying to isolate direct effects from secondary ones.

Or suppose there are only three major characters in your story, but ten secondary ones whom you don't want the reader to confuse with each other.