意馬 is read as いば (iba) and means uncontrolled.
いば
iba
いばしんえん
it is hard to keep one's worldly desires and passions in check
しんえんいば
(being unable to control) one's worldly desires and passions
いこう
intention
いしき
consciousness
いよく
will
いしけってい
decision-making
いしひょうじ
declaration of intent
いみあい
implication
いひょう
surprise
いきごみ
ardor
いきごむ
to be enthusiastic (about)
いきとうごう
hit it off with (a person)