Strongs: H2992
H2992 @ יבם yâbam yaw-bam' A primitive root of doubtful meaning; used only as a denominative from H2993 to marry a (deceased) brother´ s widow: - perform the duty of a husband´ s {brother} marry.
Genesis:38:8
Deuteronomy:25:5
Deuteronomy:25:7