From the nature of this question, my guess is that eventually you could be writing an essay on the "definition of pride." The best way to answer this is to brainstorm a list of personal feelings, experiences, and observations that you associate with pride.
Ask yourself, "When is the last time I experienced pride? What led up to the moment and how did I really feel?" Now, you have to resist the urge to write, "I don't know, I just felt proud." I know this can be hard to do.
My experiences will be far different from yours, so I'll give you a personal example. The last time I felt pride was actually the first time I saw my daughter (who is 3) pump herself on swings without any push. She had thrown a huge temper tantrum the day before when I was teaching her how, then I saw her at school, all by herself, doing it like she had been doing it her entire life. I was overwhlemed and felt successful. I felt a sincere sense of ownership at that moment, for something I had invested in my daughter. I wanted to claim her as mine in front of everyone.
Now I realize my words alone are not specifically adjectives, but perhaps they will help spark you to think about what pride really means, and come up with some on your own. Good luck.