SNR

noun3

1. •
   signal-to-noise ratio
2. •
   supernova remnant
3. •
   Initialism of Single Number Rating, a measure of the efficacy of hearing protection.

adjective1

1. •
   (UK) Abbreviation of senior; a title used after a father's name when his son is given the same name.

   • His father, Barack Obama Snr, was a visiting foreign student at university in Hawaii where he met and married Ann Dunham, the corn-fed product of Kansas parents, who was also studying at the college. — 2006