一半 is read as いっぱん (ippan) and means half.
いっぱん
ippan
いちりゅうはん
not quite first-class
いっぷんはん
a minute and a half
いちねんゆうはん
Ichinen Yūhan (book by Nakae Chōmin)
いちもんきなか
meagre sum of money
いちげんはんく
a single word
いっしはんせん
small sum
いちじはんく
いっちはんかい
superficial knowledge
ひとり
one person
いちにんまえ
adult
いちにち
1st day of the month
ひととき
two-hour period