unregardant
/(ˌ)ʌnrɪˈɡɑːd(ə)nt/Chiefly poetic. Now rare
adjective
Unobservant, inattentive; dismissive.
Origin
Mid 17th century; earliest use found in Walter Charleton (1620–1707), physician and natural philosopher. From un- + regardant, probably after unregard.