precursor /prē-kûrˈsər/

1. Something that exists or goes in advance of another
2. An indication of the approach of an event
3. A forerunner, herald or harbinger
4. A predecessor
5. A substance from which the one in question is derived or manufactured (chem)

• researching
• re-searchs
• reseat
• reseated
• reseating
• reseats
• reseaux
• resect
• resected
• resecting
• resection
• resectional
• resections
• resects
• Reseda
• Resedaceae
• Resedas
• reseize
• reseized
• reseizes
• reseizing
• reselect
• reselected
• reselecting
• reselection