Winkle and WWI

If you have ever extracted a winkle from its shell, then you understand how the verb winkle came to be. The word winkle is short for periwinkle, the name of a marine or freshwater snail. Periwinkle is ultimately derived from Latin pina, the name of a mussel, and Old English wincle, a snail shell. Evidently the personnel of World War I's Allied Powers found their duty of finding and removing the enemy from the trenches analogous to extracting a well-entrenched snail and began using winkle to describe their efforts. The action of "winkling the enemy out" was later extended to other situations, such as "winkling information out of someone."