pet·ro·chem·is·try 
(pĕt′rō-kĕmĭ-strē)
(pĕt′rō-kĕmĭ-strē)n.
1. The chemistry of petroleum and its derivatives.
2. The branch of geochemistry that deals with the chemical composition of rocks.
- Congo River
- Congo snake
- congou
- congrats
- congratulate
- congratulation
- congratulator
- congratulatory
- congregant
- congregate
- congregation
- congregational
- congregationalism
- congregationalist
- congregative
- congregator
- congress
- Congress boot
- congressional
- congressionally
- Congressional Medal of Honor
- congressman
- congressperson
- congresswoman
- Congreve