pole star

Short definition from Wiktionary

Noun

1. 1
   The star visible to the naked eye which was in the past, is now, or will be in the future nearest a celestial pole of a planet.
2. 2
   A person, principle, or thing which acts as a guide; a guiding light; also, something which attracts much attention; a centre of attention.
3. 3
   Alternative form of pole star.

Proper noun

1. 1
   Synonym of North Star, the current northern pole star, which has been Polaris for the last 1500 years.