Extended Strong's Hebrew Lexicon (Brown-Driver-Briggs based)
Onan
Usage: A man of the tribe of Judah living at the time of Egypt and Wilderness, first mentioned at Gen.38.4; son of: Judah (H3063) and Bath-shua (H1323I) ; brother of: Er (H6147) and Shelah (H7956); half-brother of: Perez (H6557) and Zerah (H2226I) § Onan = "strong" second son of Judah, slain by God for not fulfilling the levitical requirement to beget a child with the wife of a dead, childless brother