"Radiation, in physics, process of transmitting energy through space. Such radiation can consist of waves or particles. Waves and particles have many characteristics in common; usually, however, the radiation is predominantly in one form or the other. Mechanical radiation consists of waves, such as sound waves, that are transmitted only through matter. Electromagnetic radiation is independent of matter for its propagation; speed, amount, and direction of energy, however, are influenced by the presence of matter. This radiation occurs in a wide variety of energies, with visible light about in the middle of the range. Electromagnetic radiation carrying sufficient energy to bring about changes in atoms that it strikes is called ionizing radiation (see RADIATION EFFECTS, BIOLOGICAL). Particle radiation also can be ionizing if it carries enough energy. Like electromagnetic radiation, which it resembles, it does not require matter for its propagation. Examples of particle radiation are cosmic rays, alpha rays, and beta rays. Cosmic rays are streams of positively charged nuclei, mainly those of hydrogen. Cosmic rays may also contain electrons, protons, gamma rays, pions, and muons. Alpha rays are streams of positively charged helium nuclei. Beta rays are streams of electrons. (see ALPHA PARTICLE; BETA PARTICLE).
...
"Radiation," Microsoft (R) Encarta. Copyright (c) 1994 Microsoft Corporation. Copyright (c) 1994 Funk & Wagnall's Corporation."

I generally don't use the term cosmic ray instead I use the term Galactic Radiation [or GCR, Galactic Cosmic Radiation {or rays}]. At least I think the two terms are basically the same, hmm. [search]. Yeah:
"Cosmic rays are high energy charged particles, originating in outer space, that travel at nearly the speed of light and strike the Earth from all directions. Most cosmic rays are the nuclei of atoms, ranging from the lightest to the heaviest elements in the periodic table. Cosmic rays also include high energy electrons, positrons, and other subatomic particles. The term "cosmic rays" usually refers to galactic cosmic rays, which originate in sources outside the solar system, distributed throughout our Milky Way galaxy. However, this term has also come to include other classes of energetic particles in space, including nuclei and electrons accelerated in association with energetic events on the Sun (called solar energetic particles), and particles accelerated in interplanetary space."
from:
http://www.srl.caltech.edu/personnel/dick/cos_encyc.html
Also:
http://helios.gsfc.nasa.gov/cosmic.html