Burthen
noun
A heavy load.
A responsibility, onus.
A cause of worry; that which is grievous, wearisome, or oppressive.
verb
To encumber with a literal or figurative burden.
“to burden a nation with taxes”
To impose, as a load or burden; to lay or place as a burden (something heavy or objectionable).
noun
The tonnage of a ship based on the number of tuns of wine that it could carry in its holds.