Rf.

from The Century Dictionary.

• noun An abbreviation of Royal Field Artillery.
• Abbreviations of rinforzando or rinforzato.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a radioactive transuranic element which has been synthesized
• noun a substance produced by the hypothalamus that is capable of accelerating the secretion of a given hormone by the anterior pituitary gland
• noun a complex neural network in the central core of the brainstem; monitors the state of the body and functions in such processes as arousal and sleep and attention and muscle tone