noun: (Canada, US, meteorology) Followed by a number from 0 to 5: initialism of Enhanced Fujita, a rating on the Enhanced Fujita scale used to indicate the intensity of a tornado. It has superseded the Fujita scale.
noun: (medicine, cardiology) Initialism of ejection fraction. [(cardiology) The proportion of blood ejected out of the left ventricle with each heartbeat.]
noun: (computing, Microsoft) Initialism of Entity Framework, an open-source ORM framework.
noun: (Roman Catholicism) Initialism of Extraordinary Form. [(Roman Catholicism) The Tridentine liturgy according to the rubrics in force shortly before the Second Vatican Council.]
adjective: (philately) Initialism of extremely fine or extra fine; also XF.