unreasoning
adjective
un·​rea·​son·​ing
| \ ˌən-ˈrēz-niŋ
, -ˈrē-zᵊn-iŋ\
, -ˈrē-zᵊn-iŋ\
Definition of unreasoning
: not reasoning
especially
: not moderated or controlled by reason
unreasoning fear