adj.
Pronunciation: ' fa-k ə l- ˌ t ā -tiv, Brit -t ə -tiv
Function: adjective
Date: 1820
1 a : of or relating to the grant of permission, authority, or privilege < facultative legislation> b : OPTIONAL
2 : of or relating to a mental faculty
3 a : taking place under some conditions but not under others < facultative diapause> b : exhibiting an indicated lifestyle under some environmental conditions but not under others < facultative anaerobes>
– fac · ul · ta · tive · ly adverb