/bʌlk ||; bʌlk/noun1 the bulk (of sth) [sing] the main part of sth; most of sth （事物的）主要部份，大部份: The bulk of the work has been done, so we should finish this week. 这个活大部份已经干完，这个星期完成应当没问题。
2 [U] the size, quantity or weight of sth large （大型物件的）体积，数量，重量: The cupboard isn't especially heavy -- it's its bulk that makes it hard to move. 这个碗柜倒不重，只是体积大，要搬动并非易事。He slowly lifted his vast bulk out of the chair. 他挪动着肥大的身躯，慢慢地从椅子站起来。
in bulk in large quantities 大量:
If you buy in bulk, it's 10% cheaper. 大量购买，九折优待。