reasonless

adjective

rea·​son·​less ˈrē-zᵊn-ləs 

1

: not having the faculty of reason

a reasonless brute

2

: not reasoned : senseless

reasonless hostility

3

: not based on or supported by reasons

a reasonless accusation

reasonlessly adverb

Word History

First Known Use

14th century, in the meaning defined at sense 1