burthens

Noun

burthen (plural burthens)

1. (historical, obsolete) The tonnage of a ship based on the number of tuns of wine that it could carry in its holds.
   • It was a vessel of about seventy tons burthen, and shaped something like a Chinese junk.1869, Alfred Russel Wallace, The Malay Archipelago, volume II, London: Macmillan and Co., page 160
2. Rarely used musical tempo, meaning slow and ponderous (e.g., moving under a burden); similar to largo.
3. A section of music with the tempo mark burthen.