e·ra 
(îrə, ĕrə)
(îrə, ĕrə)n.
1. A period of time as reckoned from a specific date serving as the basis of its chronological system.
2. A period of time characterized by particular circumstances, events, or personages: the Colonial era of US history; the Reagan era.
3. The longest division of geologic time, made up of one or more periods.
[Late Latin aera, from Latin, counters, pl. of aes, aer-, bronze coin; see ayes- in the Appendix of Indo-European roots.]
- red herring
- redhorse
- red-hot
- redia
- redial
- redid
- redifferentiation
- redingote
- red ink
- redintegration
- redintegrative
- redintegrator
- redirect
- redirect examination
- redirection
- rediscover
- rediscovery
- redistribute
- redistribution
- redistributionist
- redistributive
- redistrict
- redivivus
- Red Jacket
- red kidney bean