Dictionary.com
Thesaurus.com

serotinal

American  
[si-rot-n-l, ser-uh-tahyn-l] / sɪˈrɒt n l, ˌsɛr əˈtaɪn l /

adjective

  1. pertaining to or occurring in late summer.


Etymology

Origin of serotinal

First recorded in 1895–1900; serotine 1 + -al 1