Now of these words we have the following;
πηὸς, for any relative by affinity;
ἐκυρὸς, πενθερὸς, father-in-law;
ἐκυρὴ, mother-in-law;
δαὴρ, brother-in-law;
γαλοὼς, sister-in-law;
γαμβρὸς, son-in-law;
νυὸς, daughter-in-law;
μητρυίη, stepmother; or the lawful wife, in relation to a spurious son. There is but one real example, Eeribœa, of a stepmother in Homer (Il. v. 389).
And, lastly, we have εἰνατεὶρ, husband’s sister-in-law, a relationship not expressed by any word in the English and many other languages. The εἰνατέρες are always separate from the γαλόῳ.