イツ, そ.れる, そ.らす, はぐ.れる, いっ, はや, へん
deviate, idleness, leisure, miss the mark, evade, elude, parry, diverge
JLPT1 G7 S11 F1524
As per 兔#/兎 rabbit (fast-moving) + 辵 movement → *be fast* and elusive → *stray*; *deviate* → *be missing*. The present form deletes one stroke from 兔. There is no etymological connection with 免.
[Full Kanji Etymology List]