cool as a cucumber

Etymology
First use appears c. 1722 in a translation of . See cite below.

Adjective

 * 1)  Calm and composed even in difficult or frustrating situations; self-possessed.
 * Even during the elections, Josh was as cool as a cucumber.
 * 1) * 1731, Jonathan Swift, Alexander Pope, Miscellanies: The Last Volume
 * Pert as a Pear-Monger I'd be,
 * If Molly were but kind;
 * Cool as a Cucumber could see
 * The rest of Womankind
 * The rest of Womankind

Translations

 * Finnish: rauhallinen kuin viilipytty
 * German: kalt wie Hundeschnauze
 * Hungarian: rendíthetetlenül nyugodt, rendíthetetlen nyugalmú, csigavérű
 * Portuguese:
 * Russian: споко́йный, как уда́в (lit: calm as a boa)
 * Spanish: estar más fresco que una lechuga
 * Swedish: ,