Luke 15:30 But as soon as this thy son was come, which hath devoured thy living with harlots, thou hast killed for him the fatted calf.
When, however, that son of yours, this the one eating up your livelihood with prostitutes comes, you kill the fattened calf.
The Greek word translated as "but" means "but", "however", and "on the other hand". Since it always falls in the second position, translating it as "however" often captures its feeling better.
"As soon as" is from the Greek adverb which means "when", "as when", "at the time when," and "sometimes."
"This" is translated from a Greek word that means "this", "that", "the nearer." This word appears after "the son".
The word translated as "thy" is the possessive form of the second person pronoun. Again, it appears after the noun "son".
The word translated as "son" more generally means "child" or "children". It begins with an article so is "the son" or "this son". The "this" from above, appears after, further accentuating it.
The word translated as "was come" primarily means "to start out" but Christ usually uses it to mean "come" but not always. It indicates movement, especially its beginning, without indicating a direction toward or away from anything, so it works either as "come" or "go," but it is more like our phrase "being underway." Our English word "show up" captures both the "start" and "come" ideas. This verb comes after "prostitutes" and before "kill" in the Greek. It is active.
The word translated as "which" is the Greek definite article, which usually precedes a noun and, without a noun, takes the meaning of "the one." The Greek article is much closer to our demonstrative pronouns ("this", "that", "these", "those"). See this article for more.
"Hath devoured" is from a verb that means "to eat up" and "to devour." It is a term applied to animals of prey. It also means "to corrode" or "to be gnawed." It is in the form of an adjective, "devouring" or "eating up".
The word translated as "thy" is the possessive form of the second person pronoun.
The Greek word translated as "living" means "livelihood", and "means of living", in the sense of supporting yourself and your family. It is not the Greek word normally translated as "life". See this article about that word and related terms.
"With" is the Greek word that usually means "with" or a related concept such as "among" or "by the means of". It also refers to "after" or "behind" when referring to a place, time, or pursuit.
"Harlots" is from the Greek word that means "prostitute." It is from a verb that means "for sale", "bought," and "ruined."
The Greek verb translated as "thou hast killed" is uncommon for Jesus. It means to "offer by burning", "sacrifice", "slay", "slaughter", "celebrate [with sacrifices, offerings]," "the flesh of the sacrifice." The sense it "sacrifice", that is, to kill and burn on an altar.
The word translated as "flr him" is the Greek word commonly translated as third-person pronouns in English. The word means "the same" when used as an adjective. The "for" comes from the indirect object form.
"Fatted" is a Greek adjective Jesus uses only in this story. It means "fed up", and "fatted". It is used as a noun and appears after "calf", "the fattened one".
"Calf" is a Greek noun that Jesus only uses in this story. It means "calf", "young bull", "any young animal", and metaphorically, "a boy", or in feminine, "a girl".
ὅτε (adv/conj) "As soon as" is hote, which means "when", "as when", "at the time when," and "sometimes."
δὲ (conj/adv) "But" is de which means "but" and "on the other hand." It is the particle that joins sentences in an adversarial way but can also be a weak connective ("and") and explanation of cause ("so") and a condition ("if").
ὁ υἱός (noun sg masc nom) "The Son" is huios, which means a "son," and more generally, a "child." It is used generally to refer to any male descendant.
σου (adj sg masc gen) "Thy" is sou which means "of you" and "your."
οὗτος (adj sg masc nom ) "This" is houtos, which as an adjective means "this", "that", "the nearer." As an adverb, it means "in this way", "therefore", "so much", "to such an extent," and "that is why."
ὁ (article sg masc nom) "Which" is the Greek definite article, which usually precedes a noun and, without a noun, takes the meaning of "the one" or, in the plural, "the ones."
καταφαγών (part sg aor act masc nom) "Hath devoured" is from katesthiô, which means "to eat up" and "to devour." It is a term applied to animals of prey. It also means "to corrode" or "to be gnawed."
σου (adj sg masc gen) "Thy" is sou which means "of you" and "your."
τὸν βίον [uncommon](noun sg masc acc) "Living" is from bios (bios), which means "mode of life", "livelihood", "means of living", "the world we live in", "a biography," and "caste."
μετὰ (prep) "With" is meta, which means "with", "in the midst of", "among", "between", "in common", "along with", "by the aid of", "in one's dealings with", "into the middle of", "coming into", "in pursuit of", "after", "behind", "according to," "after", "behind", and "next afterward."
πορνῶν (noun pl fem gen) "The harlots" is from porne, which means "harlot," and "prostitute." It is from a verb that means "for sale", "bought," and "ruined."
ἦλθεν, (verb 3rd sg aor ind act ) "Was come" is erchomai, which means "to start," "to set out", "to come", "to go," and any kind of motion. It means both "to go" on a journey and "to arrive" at a place.
ἔθυσας [uncommon] (verb 2nd sg aor ind act) "Thou hast killed" is from thyro, which means tto "offer by burning", "sacrifice", "slay", "slaughter", "celebrate [with sacrifices, offerings]," "the flesh of the sacrifice."
αὐτῷ (adj sg masc dat) "For him" is autos, which means "the same," and the reflexive pronouns, "myself", "yourself", "himself", "herself", "itself," or the oblique case of the pronouns, "him", "her," and "it." It also means "one's true self," that is, "the soul" as opposed to the body and "of one's own accord." In the adverbial form, it means "just here" or "exactly there."
τὸν σιτευτὸν , [uncommon](adj sg masc acc) "Fatted" is siteutos, which means "fed up", and "fatted".
μόσχον. (noun sg masc acc) "Calf" is moschos, which means "calf", "young bull", "any young animal", and metaphorically, "a boy", or in feminine, "a girl".