burden

Etymology 1

From Middle English burden, birden, burthen, birthen, byrthen, from Old English byrden, byrþen, from Proto-West Germanic *burþini, from *burþī, from Proto-Germanic *burþį̄, from Proto-Indo-European *bʰer- (“to carry, bear”).

noun

1. A heavy load.
2. A responsibility, onus.
3. A cause of worry; that which is grievous, wearisome, or oppressive.
   c. 1710-1730, Jonathan Swift, The Dean's Complaint Translated and Answered Deaf, giddy, helpless, left alone, / To all my friends a burden grown.
4. The capacity of a vessel, or the weight of cargo that she will carry.
   a ship of a hundred tons burden
   […] The quay is upwards of 1,000 feet in length, and capable of accommodating more than 100 sail of traders; and there are generally a considerable number of vessels of from 40 to 300 tons burden, from various parts of the world, waiting to receive their cargoes. 1945 May and June, Charles E. Lee, “The Penrhyn Railway and its Locomotives—1”, in Railway Magazine, page 142, text published 1848
5. (mining) The tops or heads of stream-work which lie over the stream of tin.
6. (metalworking) The proportion of ore and flux to fuel, in the charge of a blast furnace.
7. A fixed quantity of certain commodities.
   A burden of gad steel is 120 pounds.
8. (obsolete, rare) A birth.
   […] that bore thee at a burden two fair sons.
9. (medicine) The total amount of toxins, parasites, cancer cells, plaque or similar present in an organism.

verb

1. (transitive) To encumber with a literal or figurative burden.
   to burden a nation with taxes
2. (transitive) To impose, as a load or burden; to lay or place as a burden (something heavy or objectionable).

Etymology 2

Inherited from Middle English burdoun (“accompaniment”), from Old French bordon (“drone”), from Medieval Latin burdō. Doublet of bourdon.

noun

1. (music) A phrase or theme that recurs at the end of each verse in a folk song or ballad.
   As commonly used, the refrain, or burden, not only is limited to lyric verse, but depends for its impression upon the force of monotone - both in sound and thought. 1846, Edgar Allan Poe, The Philosophy of Composition
2. The drone of a bagpipe.
   BURDEN in some musical instruments, the Drone or Bass , and the pipe or string that plays it 1740, Sébastien de Brossard, James Grassineau, A Musical Dictionary
3. Theme, core idea.
   the burden of the argument