dan

noun7

1. •
   A rank of black belt in martial arts.
2. •
   Someone who has achieved a level of black belt.
3. •
   A traditional unit of equivalent volume, now officially equal to 100 liters.
4. •
   Synonym of picul: a traditional unit of weight and mass, chiefly used as a dry measure of grains.
5. •
   A dan buoy.

   • Carrying away of 25 great-lines, 3 dans, buoys, &c., of steam liner 'Star of the East'[…] — 1913
6. •
   A small truck or sledge used in coal mines.
7. •
   (no longer used) A title of honour or respect similar to "master" or "Sir", used of historical and legendary figures of the past.

   • Dan Phoebus, he with many a low'ring look / Had her beheld in yore in angry wise. — 1578

noun2

1. •
   Acronym of Dynamic Albedo of Neutrons, a scientific instrument of the Mars Science Laboratory onboard the Curiosity rover at Mars.
2. •
   Acronym of deadenylating nuclease, a protein that binds the 5' cap of mRNA and begins degradation in the 3' to 5' direction.