Visual: This word seems a strange syncretism: the smooth mass of mammo exploding into the ripped mess of thrept. It’s like a string of firecrackers half exploded. Smooth bumps to the left; torn thorns to the right. Overall, long.
In the mouth: There’s little depth to this word: the consonants are almost all on the lips, except for a trip of the tip of the tongue across the teeth and ridge. The vowels are towards the front, going no farther back than the neutral reduced vowel in the middle. The word starts off soft and humming but then, as if a snare has been tripped, turns to the voiceless. And while the first two syllables are simple consonant-vowel, the last is a thick cluster of four consonants nesting just one vowel.
Echoes: You can’t avoid the mammoth. But also think of mammal and mammogram. And then, at the other end of the size scale from a mammoth, you have thrip, along with trip and rep and ripped and stripped perhaps threat. And maybe even strep throat. I suppose if you think about it you could find stripling, but that’s faint at best (mama’s stripling? hmmm). The ending also makes me think of bankrupt.
Etymology: This comes from Greek μαμμόθρεπτος mammóthreptos ‘brought up by grandmother’ (‘grandmother’ being μάμμη), by way of Latin mammothreptus ‘kept at the breast too long’. It has no relation to mammoth, which comes, somewhat modified, from Russian.
Semantics: A mammothrept, in English, is a spoiled child, or someone of immature judgement. This word is a silver salver version of twerp or douchebag.
Overtones: This word is obviously a very erudite insult. The odds are quite good that your hearer will not know its meaning until you explain it, but as long as you say it with the right intonation and in the right context, the general sense is likely to be clear. It has a sound of a muttering and a spitting, and it has about that taste, too, but coming from not an urchin but a dowager duchess.
Where to find it: You’ll find it in a play by Ben Jonson and a novel by Patrick O’Brian, and not much in between. But once you show this word to your friends, you’re sure to see it here and there in their writings.
How to use it: This word isn’t like an ace in the card game of conversation. It’s like slapping down an odd stone as your bet – a stone that could be priceless or worthless, but no one at the table probably knows which. It’s a big woolly mammoth ripping through the grass of verbiage. Use it in writing when you know your readers will look it up. Use it in speech when you can say it with about the same sound and tone as “Mmm, I’m’a throw up.” Make sure you say it so that it clearly starts with a “mamma” and not a “mammoth.”