an·es·trus 
(ăn-ĕstrəs)
(ăn-ĕstrəs)n.
An interval of sexual inactivity between two periods of estrus in female mammals that breed cyclically.
- circumstantial
- circumstantial evidence
- circumstantiality
- circumstantially
- circumstantiate
- circumstantiation
- circumstellar
- circumterrestrial
- circumvallate
- circumvallation
- circumvent
- circumventer
- circumvention
- circumventive
- circumventor
- circumvolution
- circumvolve
- circus
- circusy
- cire
- cirque
- cirrate
- cirrhosis
- cirrhotic
- cirri