noun, verb (used with object) Archaic.
Related formsbur·then·some, adjective
Examples from the Web for burthen
The fraudulent possessor of the notes felt their burthen more than ever insupportable.Young Mr. Barter's Repentance|David Christie Murray
A quibble is intended between as the conditional particle, and ass the beast of burthen.Notes to Shakespeare, Volume III: The Tragedies|Samuel Johnson
The burthen of proof lies upon the affirmant: and the proof produced must be open to the scrutiny of every dissentient.
Lucy now reappeared with her apron so loaded with nuts, that she could with difficulty support the burthen.The Betrothed|Alessandro Manzoni
So large of limb, his joints so strongly knit, Such breadth of shoulders as might mainly bear Old Atlas' burthen.