The LXX has Χαναναία in Zechariah 14:21, with other forms of the same word found many times elsewhere in the Old Testament, and also once in the New, Matthew 15:22, where the KJV has the same word as the LXX (Strong's G5478).
Looking further at the instances in the LXX (canonical books), it almost disappears after the book of Judges, where it appears in Proverbs 31:24 (KJV as "merchant"), 2 Samuel 23:8 (KJV as "Tachmonite"), 2 Samuel 24:7 (KJV as "the Canaanites"), Hosea 4:18 (obscure connection to the KJV text), Obadiah 1:20 (KJV as "the Canaanites"), Zechariah 11:11 (obscure connection in KJV text as "the poor" of the flock, but the NASB has a footnote "sheep dealers"); and Zechariah 14:21 (KJV as "Canaanite").
The fact that usage of the word dwindles to a trickle beyond Judges, indicates to me that the people group who were once referred to as Χαναναία in the LXX, must have all but disappeared from the land.
From the evidence available to me, the word is best translated Canaanite, and any other rendering would require a footnote to provide some reason for not doing so.
Based on some feedback in the comments, I thought I'd have a closer look at why Χαναναία appears in Hosea, Obadiah and Zechariah. Are the prophets using the word to refer to people they've encountered, or to a people group who have historically been the very antithesis of what God wants Israel to be?
I believe it is the latter.
ᾑρέτισεν | Χαναναίους | πορνεύοντες | ἐξεπόρνευσαν
They chose| Canaanites |to fornicate (with)| to prostitute themselves
ἠγάπησαν | ἀτιμίαν | ἐκ | φρυάγματος | αὐτῶν
They loved| (the) dishonour | from | ?????????? | their
φρυάγματος has no entry in the LXX lexicon, so it is a bit of a mystery. In my initial attempt at this word, I searched for "αγματ" that yielded πραγματος deed, Strong's H4229, which I thought might be a distinct possibility. However, additional feedback from the comments led me to the lexicon at the Greek Word Study Tool, where the word refers to the "snorting" of horses. Some might prefer the figurative use of the word as "insolence", but I think the literal sense works better in the context. So Hosea 4:18 might then read:
They chose Canaanites to fornicate with, prostituting themselves. They delighted in the indignity of their snorting.
It is a direct reference to Israel's willingness, historically -- from the very beginning of her journey into Canaan, even up until the time of Hosea -- to be wooed and ravished by the god's of Canaan instead of remaining faithful to the Lord.
The context of Χαναναία, here, is: the land that was promised to Israel as a possession, "that of the Canaanites", the people of the Captivity would return to re-possess. As for those who had interfered with the assignment/charge given to Israel to go in and possess the land, "the day of the LORD" was nigh upon them.
καὶ | διασκεδασθήσεται | ἐν | τῇ | ἡμέρᾳ
And the | ?????????? | in | the | day
ἐκείνῃ| καὶ | γνώσονται | οἱ | Χαναναῖοι
that | also | will know | the | Canaanite
τὰ | πρόβατα | τὰ |φυλασσόμενα | διότι
the | sheepfold | the | guarded | because
λόγος | κυρίου | ἐστίν
word | (of the) Lord | is
διασκεδασθήσεται has no entry in the LXX lexicon, but searching for "διασκ*" yielded διασκορπιζων (scatter, Strong's G1287. A similar looking word appears in the LXX in the previous verse where the KJV has "cut assunder", which indicates to me, it might mean something like "shattered". So, Zechariah 11:11 would then read:
At the shattering [of Beauty] in that day, even the Canaanites will understand that the sheepfold is protected, because of the word (Logos) of the Lord.
The context of this verse is:
the nations will be gathered against Jerusalem, and it will fall;
God will come and fight against the invaders;
various signs - earthquake, dim light (no night or day), living water flowing from Jerusalem - will mark the day as unique;
Then "The LORD will be king over the whole earth. On that day there will be one LORD, and his name the only name.".
Jerusalem will be raised up high, and will be forever secure.
Dreadful plagues and panic will strike the nations, but those who survive will come annually to Jerusalem to celebrate the Feast of Tabernacles.
Those who refuse to come will suffer great drought.
Zechariah 14:21 concludes this vision of the future: "there will no longer be a Canaanite in the house of the LORD Almighty."
The impression I get from the usage of Χαναναία in these verses is: Canaanites (Χαναναία) are those whose hearts are set on rebellion against God's rule and authority, who would persist with, and/or encourage others to persist with, the abominable behaviour that caused the land of Canaan to spew its people out.
The reason there will no longer be a Canaanite in the house of the Lord is: if he be of a Canaanite heart, then his refusal to come will see him destroyed by the plagues and panic and drought of the day of the Lord. If, however, his Canaanite heart were converted and he come to Jerusalem to worship the Lord and to celebrate the Feast of Tabernacles, then he would no longer be of a Canaanite heart, i.e. not a Canaanite.