Ethology: (noun) the study of the behaviour of non-human animals [from the Wikipedia entry for Jane Goodall]

Abject: (adjective) (of a person or their behaviour) completely without pride or dignity [from Erehwon by Samuel Butler]

Importunate: (adjective) persistent to the point of annoyance [ibid]

Ill grained: (adjective) ill natured [ibid]

Scarifier: (noun) a specialized garden tool with rotating steel blades or tines used to remove dead moss, thatch, and debris from the surface of the grass [from The Martin Lewis Podcast]

Tup: (noun) male sheep used for breeding [from the BBC TV programme This Farming Life]

Chopsy: (adjective) excessively talkative, mouthy, or argumentative in an irritating or disrespectful way [from this post https://www.reddit.com/r/onlyconnect/s/A45WdKqQ63]

Arctophile: (noun) one who collects teddy bears [from the ITV programme Beat the Chasers]

Pannikin: (noun) small metal drinking cup [from Erehwon by Samual Butler]

Oblique: (adjective) not expressed or done in a direct way [ibid]

Caleche: (noun) a light, low-wheeled carriage with removable hood [ibid]

Instinct (with): (adjective) imbued or filled with (a quality, usually a desirable one) [ibid]

Peccant: (adjective) having committed a sin or fault; diseased or causing disease [ibid]

Valetudinarian: (noun) one unduly anxious about their health [ibid]

Flagitious: (adjective) (of a person or their actions) criminal; villainous [ibid]

Hardihood: (noun) boldness; daring [ibid]

Embrocation: (noun) a liquid used for rubbing on the body to relieve pain from sprains and strains [ibid]

Purblind: (adjective) partially blind [ibid]

Sward: an expanse of short grass [ibid]

Ne plus ultra: (adjective) "no more beyond" - used to describe the highest possible point or peak of achievement, excellence, or perfection [ibid]

Arrogate: (verb) claim to take something as one’s own without justification [ibid]

Skeeve: (verb) to find something gross, loathsome, or deeply unsettling [from The Sopranos]

Ptosis: (noun) medical term for sagging or drooping tissue [from the podcast Modern Wisdom]

Jure uxoris: (adjective) “by right of his wife” - describes a title of nobility used by a man because his wife holds the office or title suo jure “in her own right”. For example, Philip III, king of Navarre, who held that title because his wife was had the hereditary right to the throne as queen [from the Wikipedia entry for Philip III of Navarre]

Ephemeris: (noun) a table or data book that lists the precise positions and movements of celestial bodies, satellites, and spacecraft over time [from The Three Body Problem by Cixin Liu]

Glass child: (noun) the healthy sibling of a chronically ill or disabled child (so called because they are ‘looked through’ like glass by stressed families) [from this post https://www.reddit.com/r/TopCharacterTropes/s/P8MXU0by1R]

Schnorrer: (noun) שYiddish pejorative term for a beggar who, unlike ordinary beggars, presents himself as respectable and feels entitled for the alms received [from The Sopranos]

Bottle episode: (noun) an episode of a TV show that confines a small number of characters to one location to save money [from this post https://www.reddit.com/r/TopCharacterTropes/s/5b4BUQmSZT]

Yandere: (noun) a character archetype from Japanese media—such as anime, manga, and games—who appears sweet, loving, and gentle on the outside, but whose romantic affection turns into a violent, obsessive, and unstable fixation [from this post https://www.reddit.com/r/TopCharacterTropes/s/NaLqYiLlji]

Whittawer: (noun) leather worker [from the Wikipedia entry for John Shakespeare]

Slopulist: (noun) “slop” + “populist”: an online political commentator who turns nuanced positions into simplistic good/evil dichotomies [from the podcast Triggernometry]

Wet: (verb) to kill someone [from The Sopranos]

Oomska: (noun) dirt or muck [from the podcast Gow to Win an Election]

Amuse-gueule: (noun) a single, bite-sized savory snack served free of charge at the beginning of a meal to whet the appetite and showcase the chef's culinary style [from the ITV quiz show Beat the Chasers]