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)

• unreformed
• unrefracted
• unrefreshed
• unrefreshing
• unrefuted
• unregarded
• unregarding
• unregeneracies
• unregeneracy
• unregenerate
• unregenerated
• unregimented
• unregistered
• unregulated
• unrehearsed
• unrein
• unreined
• unreining
• unreins
• unrejoiced
• unrejoicing
• unrelated
• unrelative
• unrelaxed
• unreleased