Under the Whyte notation system, a steam locomotive that has ten coupled driving wheels followed by two trailing wheels, with no leading wheels.

(organic chemistry) The common name for undecylenic acid.

plural of A-109

(aviation) The Agusta A109 twin-engine utility helicopter.

plural of A-106

(aviation) The Agusta A.106 prototype helicopter, which never made it into pre-production.

US standard spelling of 10000 metres.

(aviation, slang) A general aviation flight that involves flying a short distance, eating a meal, and flying back. / Used other than figuratively or idiomatically: see $, 100, hamburger.

A flood event that has a 1% probability of occurring in any given year; an exceptionally large flood.

plural of $100 hamburger