leonardjayawardena wrote:So it appears that there are no single words for "step-brother" and "step-sister" in ancient Greek. Are there cases in classical or later Greek (without Semitic influence) where a step-brother or step-sister is referred to as simply ἀδελφὸς or adelphē, respectively (with οὐχ ὁμοπάτριος or οὐχ ὁμομήτριος omitted)?
My particular interest is the use of ἀδελφὸς in Mark 6:17, where Phillip is called Herod's 'brother," whereas in fact he was the latter's step-brother. I am interested in establishing whether the use of ἀδελφὸς in this verse to refer to a step-brother (assuming "Mark" meant a step-brother) falls within the classical Greek usage/idiom and so no Semitic influence need be seen here.
If you are asking about what ἀδελφός / ἀδελφή could mean, that is another question. It really depends on who is using it.
ἀδελφός is not a technical word with a single definition (externally defined meaning that is true in all circumstances). You need a different model to understand it, one that is more contextual. Brother is individual for each person, the boy in your household, that you grew up with, not something universally recognisable like Mohs scale of mineral hardness
Even if the word was used in a particular sense without semitic influence, that wouldn't show that it was the "true" sense of the word. Finding the meaning in classical Greek, is not really going to prove whether or not the meaniing at another time was because of any or no other influence. The meaning it had in that other contexts would be because of the way of thinking at that
time, not because of not thinking something at a different time. If you really want to see the breadth of meaning of this word, consider that in Egypt, there is mention of an ἀδελφή in the sense of "wife".
Are you working from a dictionary? You'll probably need to look at a few of them. While you're considering ἀδελφός you might like to look up ἐξάδελφος (a later synonym), and κασίγνητος (an earlier synonym) as well.
I guess there must be some references and studies you could look up. What you are asking seems to be grounded in language, but in fact it goes way beyond that, into considerations of culture, religion and even law.
Ὃς μὲν κρίνει ἡμέραν παρ’ ἡμέραν, ὃς δὲ κρίνει πᾶσαν ἡμέραν. Ἕκαστος ἐν τῷ ἰδίῳ νοῒ πληροφορείσθω. (Romans 14:5)