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acerebral should not be confused with "a cerebral" (an intellectual). Acerebral is an adjective that means "brainless".
agelast isn't a compliment about someone's longevity. An agelast is someone who never laughs.
alliaceous sounds sexy but it really isn't, unless you have a peculiar fetish; it means smelling or tasting like garlic.
azoic is a step further than "stoic" (patient endurance); it means "lifeless".
cepaceous. If someone calls you "cepaceous", then they are comparing you to an onion. Perhaps you are alliaceous?
errhine for some reason sounds like a compliment, but it actually means "promoting nasal discharge". Ew!
erinaceous also sounds like a compliment, but it actually means "of the nature of a hedgehog".
eructation. If you compliment someone's eructation, you're not talking about their erudition or education; you're talking about their belching.
esurient, an adjective and a noun, sounds reassuring and certain. But it means "a greedy person".
gammerstang has a go-getting sound to it. But it means "a tall awkward woman".
honeyfugle sounds like a cute pet name for your partner. But it's probably only really suitable for a certain type of partner; "honeyfugle" means "to swindle or cheat".
inaniloquent should not be confused with eloquent. It means "full of idle talk".
lurdane sounds a bit like urbane (suave). But it means "a stupid or lazy person".
macilent has a magnificent, mellifluous sound to it. But it means "lacking in substance or value".
mephitic. "That's mephitic!" might sound like a gushing compliment. But it means "foul-smelling".
nescience sounds a bit like prescience (foreknowledge). But it is almost the opposite. It means "ignorance".
nocent sounds innocent. But it is the exact opposite, meaning "guilty", or, in another sense, "harmful".
onerable isn't honourable; it means "burdensome" or "troublesome" (the word onerous comes from the same root word).
ozostomia sounds quite euphoric or even utopian. But you don't want to be in the state of ozostomia. It means "bad breath".
phlyarologist sounds like an impressive title or occupation. But it means "someone who talks nonsense".
superbious. Sick of your supervisor? Call them superbious. They may think it means "superb". But it actually also means "overbearing".
testudineous sounds resilient. But it actually means "as slow as a tortoise".
tragomaschalia. Perhaps you have a boss who thinks he is "all that"? You know — the muscle-bound, macho, jock-type. Compliment him on his tragomaschalia and you will be saying he has smelly armpits.
widdiful is a wonderful widdle word. But its cuteness belies its meaning; it means "someone who deserves to be hanged".
Apart from a bit of fun, this list of insulting words that sound innocent shows the power of a good vocabulary. If you can command words, then you can command people. To develop your vocabulary, try the popular vocabulary-building software Ultimate Vocabulary.
*Denise and I recommend only products that we have tried and tested. These include Ultimate Vocabulary. We have agreed to receive a commission from some sales of Ultimate Vocabulary because we are happy to endorse that software.