- flatten (v.)
[flatten 词源字典]
- late 14c., "to prostrate oneself," also "to fall flat," from flat (adj.) + -en (1). Transitive meaning "to make flat" is 1620s. Related: Flattened; flattening. [flatten etymology, flatten origin, 英语词源]
- pancake (v.)
- "to squeeze flat," 1879, from pancake (n.). Later, of aircraft, "to fall flat" (1911), with figurative extension. Related: Pancaked; pancaking.