Hal in Tavis's waiting room (Language and Grammar)
The Moms was snapping her fingers silently and working her forehead. ‘There’s some term for coals reduced to residue after all day in a grill. I’m trying to think.’ Hal hates this. ‘Clinkers,’ he said instantly. ‘From klinker low German and klinckaerd old Dutch, to sound, ring, nominated to substantive around 1769: a hard mass formed by the fusion of the earthy impurities of like coal, iron ore, limestone.’ He hated it that she could even dream he’d be taken in by the aphasiac furrowing and finger-snapping, and then that he’s always so pleased to play along. Is it showing off if you hate it? ‘Clinker.’ ‘A grill wouldn’t have clinkers. Charcoal’s refined to burn right down to dust. Clinkers are sort of metallic, I think. See for example the ring-dash-sound etymology.’
Context
August flashback inside the waiting-room chapter — the long Hal–Avril two-hander. Avril stages a fake word-retrieval failure, complete with finger-snapping; Hal supplies the term "instantly," with source-language etymology and date of substantivization, O.E.D.-entry format intact — hating the routine, seeing through it, playing along anyway, then extending the pedantry unprompted. The prodigy mechanism, the mother who built and still operates it, and Hal's own uneasy question about the whole transaction — "Is it showing off if you hate it?" — in one exchange. The mother-son version of the professional-conversationalist scene.