Bur·den n. [Written also burthen.]
1. That which is borne or carried; a load.
Plants with goodly burden bowing. --Shak.
2. That which is borne with labor or difficulty; that which is grievous, wearisome, or oppressive.
Deaf, giddy, helpless, left alone,
To all my friends a burden grown. --Swift.
3. The capacity of a vessel, or the weight of cargo that she will carry; as, a ship of a hundred tons burden.
4. Mining The tops or heads of stream-work which lie over the stream of tin.
5. Metal. The proportion of ore and flux to fuel, in the charge of a blast furnace.
6. A fixed quantity of certain commodities; as, a burden of gad steel, 120 pounds.
7. A birth. [Obs. & R.]
Beast of burden, an animal employed in carrying burdens.
Burden of proof
Syn: -- Burden, Load.
Usage: A burden is, in the literal sense, a weight to be borne; a load is something laid upon us to be carried. Hence, when used figuratively, there is usually a difference between the two words. Our burdens may be of such a nature that we feel bound to bear them cheerfully or without complaint. They may arise from the nature of our situation; they may be allotments of Providence; they may be the consequences of our errors. What is upon us, as a load, we commonly carry with greater reluctance or sense of oppression. Men often find the charge of their own families to be a burden; but if to this be added a load of care for others, the pressure is usually serve and irksome.
burden of proof
n : the duty of proving a disputed charge