G: TL;DR: I can’t find any solid, primary-source statement from Technōs that “Abobo” means something specific in Japanese. The most defensible read is: it’s a made-up, rhythmic, caveman-boss name chosen for sound. The best “reasonable speculation” buckets are (1) baby-talk / gurgling-style onomatopoeia, (2) “foreign-name vibe” (e.g., faint “Abu-/Arabic” flavor), and (3) coincidence with real-world names/places (notably Abobo in Côte d’Ivoire), but there’s no evidence the game referenced those.

証拠（しょうこ）は少（すく）ない。 — The evidence is thin.
名前（なまえ）は音（おと）で決（き）まることもある。 — Sometimes a name is chosen for its sound.

What’s actually findable (and what it suggests)

1) In Japanese usage, “あぼぼ(ぼぼぼ…)” exists as a sound effect, not a word-name

Modern Japanese internet/streamer usage includes あぼぼぼぼ as a kind of “glub/glub” or flustered/gurgling silly sound (you’ll see it written exactly like that in Japanese commentary about “sinking” or muffled noises). citeturn1search7
That doesn’t prove Technōs used it that way in 1987, but it supports the idea that “abobo” fits Japanese onomatopoeia / baby-talk phonetics: repeating open vowels + simple consonants = easy “big dumb brute” vibe.

Speculation strength: medium (phonetic plausibility), low (direct historical linkage).

2) Contemporary Japanese fan commentary explicitly treats it as “a weird name” with an exotic vibe

One Japanese write-up you can find online basically jokes that it “sounds like an Arab genie name” (paraphrasing the snippet), and then moves on. citeturn3search1
That’s not etymology, but it’s a clue about how Japanese speakers hear it: foreign-sounding nonsense, not “oh that’s clearly derived from X Japanese word.”

Speculation strength: medium (supports “sound-first naming”).

3) There is a real place called Abobo (Abidjan, Côte d’Ivoire)… but it’s likely unrelated

“Abobo” is the name of a large commune/suburb of Abidjan. citeturn3search2
And there are sources discussing the place-name’s meaning in local context. citeturn3search17
However: there’s no evidence Technōs referenced this, and it would be a pretty random pull for a Japanese arcade brawler in 1987.

Speculation strength: low (possible coincidence).

4) Even within the franchise, boss naming was messy early on

Secondary sources (wikis/magazine recollections) suggest early print materials used different names or applied “Abobo” inconsistently to variants. citeturn1search1
This tends to correlate with “Abobo” being a label that stuck more than a carefully constructed name with meaning.

Speculation strength: medium (about naming practices, not meaning).

The most “sensical” origin hypothesis

Sound-design naming: “Abobo” as a mouth-feel for a brute

If you treat it like your “Scizzy” example: not a dictionary word, but a phonetic character sketch.

Repeated “bo” has a blunt, percussive feel (in Japanese too: ボ is a “thumpy” syllable).
Open vowels (a/o) read big and simple.
Reduplication is extremely common in Japanese playful speech (and in character naming generally).

So: not a portmanteau, more like onomatopoeic / rhythmic gibberish engineered to feel like “huge, dumb, dangerous.”

Third option I considered (and why it’s weaker)

A hidden literary/reference source (Buddhist/Sanskrit/Chinese glossaries, etc.)

You can find “abobo”/similar strings in unrelated dictionary/glossary contexts (because lots of languages produce these syllables), but none of that connects to Technōs or Double Dragon, and it’s the classic false-positive trap. citeturn0search4

Bottom line

If you want a single answer that’s maximally honest: “Abobo” is almost certainly a sound-first nonsense name that happens to resemble various real strings (places, glossaries, etc.) but doesn’t reliably trace to them. The only “reasonable” linguistic angle that fits both Japanese phonetics and the character concept is onomatopoeic / baby-talk-ish rhythmic naming rather than a hidden pun.