You haven't put any of USM Pokemon in, so wynaut?
Stakataka- The words Stack and Attack, whereas the Japanese is a repetition of the word Lay, like laying bricks.
Blacephalon- Blast and cephalo- meaning head. Its Japanese name (ズガドーン) Zugadōn means "head goes boom". Fitting :P
Poipole is a combination of poison and pole. It is also a play on purple. Bevenom is a combination of baby or bébé (French for baby) and venom
Naganadel is a combination of Nāga and Nadel (German for needle). Āgoyon may be a combination of 顎 ago (jaw), ago (Italian for needle), 四 yon (four), and dragon or 용 yong (Korean for dragon).
Zeraora may be a combination of زر zarra (Arabic for to beam/glitter/shine, to encroach upon one's enemy) and 虎 tora (Japanese for tiger) or tora (Faroese for thunder).
These are some I think are wrong (I am yet to check the full list, and will not post repeats from other answers)
Xurkitree- Needs Tree. If you look at it in the ultra plant, it looks like a tree. Also worth noting: its wires are kept together by bands that have leaves, and its Japanese name has (樹木 jumoku) tree in it.
Kartana- Need something paper related, it has that in every other language. Like charta (Latin for paper) could be it.
Solgaleo- May have Galileo in it
Vikavolt- Vice, maybe, but every language uses stag beetle and cannon. It is more likely (or both) wicga (Old English for insect).
Rowlet- more likely round rather than arrow; the Japanese is wood & owlett.
Diancie- May also have fancy/Pixi in the etymology
Goomy- (Sticky and goo) umm gooey?
Sliggoo- (Slime, Goo) maybe slug too?
Carbink- (carbon, clink) could also be carbuncle (gemstone), and carat (still carbon). This also makes more sense because other languages use carbon, small, stone, diamond, and carat in the name.
Spritzee- May have Fee- German for fairy
Fennekin- Kin may reference kindle and not kin
Chespin- you put porcupine, very wrong... every language uses hedgehog, chestnut, and needle. It could be pin(needle), urchin(old term for hedgehog), chinkapin (chestnut species), or spina - Latin for Thorn.
Genesect- Being the Paleozoic Pokemon and is Old and Ancient, Genetic could also be Genesis- This both looks more accurate and makes as much sense
Meloetta- Etta is a feminine Italian suffix meaning small, which could refer to it being small and have a female appearance.
Kyurem- may have either 無 (mu) meaning nothing, or 零 (rei) meaning zero. This makes sense because Reshiram and Zekrom are based of off ying and yang, while Kyurem represents wuji, the absence of ying and yang.
Axew- Askew makes little sense; it is more likely hew (to chop a material with a tool) or chew.
Eelektross- more likely boss instead of gross, especially when the Japanese has Don (latin for Lord) in it.
Swanna- May have Ballerina as well as swan.
Archen- Rather than chicken, it is more likely the Archean geological eon.
That is as far as I got; will check more soon :P