O Israel
Yisra'el (yis-raw-ale')
he will rule as God; Jisrael, a symbolical name of Jacob; also (typically) of his posterity: --Israel.
return
shuwb (shoob)
to turn back (hence, away) transitively or intransitively, literally or figuratively
unto the LORD
Yhovah (yeh-ho-vaw')
(the) self-Existent or Eternal; Jehovah, Jewish national name of God -- Jehovah, the Lord.
thy God
'elohiym (el-o-heem')
angels, exceeding, God (gods)(-dess, -ly), (very) great, judges, mighty.
for thou hast fallen
kashal (kaw-shal')
to totter or waver (through weakness of the legs, especially the ankle); by implication, to falter, stumble, faint or fall
by thine iniquity
`avon (aw-vone')
perversity, i.e. (moral) evil -- fault, iniquity, mischeif, punishment (of iniquity), sin.