Strong's G3994 · Greek

πενθερά

penthera · pen-ther-ah'

feminine of 3995; a wife's mother

Scholarly Lexicons

Abbott-Smith Manual Greek Lexicon

 6 πενθερά , -ᾶς, ἡ (fem. of πενθερός ), [in LXX for חָמוֹת ;] a mother-in-law : Mt 8:14 10:35 , Mk 1:30 , Lk 4:38 12:53 .† 

G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain