transitive verb
1. : to dispose of : clean up
have heard much less of Brighton's race gangs since the war, so let us hope that they have been mopped up — S.P.B.Mais
specifically : to follow in the wake of an attacking military force and clear (an area) of remaining pockets of resistance
the bulk of the troops were still needed to guard and mop up the captured territory — Infantry Journal
it was left to Australians to mop up the bypassed Japanese — D.L.Oliver
2. : to take up or assimilate : garner , absorb
urchins are abundant in nearby waters and are … mopped up by the tubful — W.C.Allee
added seventeen swimming and diving gold medals to the 56 they had mopped up in other events — Newsweek
contributes to antiinflation … in that it mops up funds that might otherwise be paid out in higher wages and dividends — W.H.Anderson
sales of assets will serve to mop up surplus credit — W.M.Dacey
intransitive verb
: to complete a project or transaction : clean up
most of the East Cambridge apparatus was mopping up at the two engine house fires — Springfield (Massachusetts) Union
quick-freezers, whose products were not rationed, mopped up on the home front — Harper's
specifically : to carry out a military cleanup
behind it would come truck-borne infantry and mobile guns to mop up and to widen the breach — Tom Wintringham