The 'bucketful' groupThese nouns refer to an amount of people or things, usually a large amount. The noun group begins with the determiner the.
This use is productive: many nouns that refer to a container can be combined with -ful and used in this pattern, and many nouns that refer to a form of transport can be combined with -load and used in this pattern. We list below the most frequent.
by the armful by the bucketful by the busload by the fistful by the handful by the lorryload by the sackful by the truckload
They gathered apples, stored them on wooden shelves in the first of the stone houses of the farmyard, and sold them by the bucketful.
My father used to buy drugs by the truckload.