From HomoExcelsior

(SNR) 1. The ratio of pertinent data to extraneous data, especially in electronic telecommunications systems. 2. Any means of rating the relevance of content in a communication, as in "His speech had a high signal to noise ratio and I think everyone found it timely and relevant", or "Because the phone lines are so bad, my modem connection has a terrible low signal to noise ratio, making it impossible to transfer data."

See also: noise, gain

---