Wiktionary
hoover up
vb. 1 (context transitive English) To suck (something) into a vacuum cleaner, irrespective of brand 2 (context transitive idiomatic English) To eat (food) quickly, especially by taking it into the mouth directly from the plate rather than using cutlery. 3 (context figuratively English) To avidly absorb something as if by a vacuum cleaner.
Usage examples of "hoover up".
It headed straight for the table and I realized it probably came in every night about this time to hoover up any dinner bits that had fallen on the floor.