Dictionary entry

πενθερός

G. Abbott-Smith's A Manual Greek Lexicon of the New Testament with Strong's

πενθερός, -οῦ, ὁ,

[in LXX chiefly for חָם, Ge 38:13, al.; also for חֹתֵן, Jg 1:16 A;]

a father-in-law: Jo 18:13.†