
Ian McEwan
https://www.merriam-webster.com/dictionary/quiddity
Quiddity
quid·di·ty | \ ˈkwi-də-tē \
plural quiddities
Definition of quiddity
1: whatever makes something the type that it is : ESSENCE
2a: a trifling point : QUIBBLE
b: CROTCHET, ECCENTRICITY
