一事 is read as いちじ (ichiji) and means one thing.
いちじ
ichiji
いちだいじ
important matter
しごとだいいちしゅぎ
workaholism
だいいちじしゃんはいじへん
Shanghai Incident (1932)
いちげん
single word
いっか
(one's own) style
いちや
one night
いっしき
same tendency
いちど
temporarily
いっぽう
on the one hand
いったい
one Buddhist image (or carving, etc.)
いちぶつ
penis
いちいん
one person