1) (of rats, insects, robbers etc) to be present in large numbers in (a building etc) (infest)

2) a constant flowing in of large numbers or quantities (influx)

3) (of music) popular; singers and players whose records sell in large numbers and who are popular on radio, TV and in discos; a short sharp, explosive sound (pop)

4) to exist or increase in large numbers (proliferate)

5) the eggs of fish and certain water animals, e.g. frogs; to produce (something) in large numbers (spawn)

6) to fall heavily (with rain); to be present, have, in large numbers (teem)

7) to face, bend, outwards; (of people) to come out in large numbers (turn-out)