From Old English 'byrthen' (a load), from PIE *bher- (to carry) — literally 'that which is borne.'
A heavy load; something that is carried with difficulty; a duty or responsibility that causes worry or hardship.
From Old English "byrðen" (a load, weight, charge, duty), derived from the verb "beran" (to bear, carry), with the abstract noun suffix "-ðen" (forming nouns of action or result). "Beran" descends from Proto-Germanic *beraną (to bear, carry), from PIE *bʰer- (to bear, carry, bring). This PIE root is one of the most productive in the language family, yielding Latin "ferre" (to carry, whence "transfer," "refer," "fertile"), Greek "phérō" (I carry),
PIE *bʰer- (to carry) is one of the busiest roots in English. Through Germanic: 'bear' (to carry), 'burden' (what is carried), 'birth' (what is borne), 'born,' 'bier' (a frame for carrying a coffin), 'barrow' (a carrying-mound or wheel-cart). Through Latin 'ferre' (to carry): 'transfer' (carry across), 'refer' (carry back