1bulk 
/ˈbʌlk/ noun
/ˈbʌlk/ noun 1 the bulk : most of something : the largest part of something
▪ We spent the bulk of the summer at the beach. ▪ Farming makes up the bulk of the country's economy. ▪ The great bulk of these people are extremely poor. 2 [noncount] : the large size of someone or something
▪ Despite his bulk, he's a very fast runner. ▪ The sheer weight and bulk of the car makes it safe to drive. [=the car is safe because it is heavy and large]
▪ We spent the bulk of the summer at the beach. ▪ Farming makes up the bulk of the country's economy. ▪ The great bulk of these people are extremely poor.
▪ Despite his bulk, he's a very fast runner. ▪ The sheer weight and bulk of the car makes it safe to drive. [=the car is safe because it is heavy and large]
in bulk
: in large containers or in large amounts
▪ The restaurant buys rice and flour in bulk. [=it buys large bags of rice and flour]
▪ The restaurant buys rice and flour in bulk. [=it buys large bags of rice and flour]
