Definition of lap noun from the Oxford Advanced American Dictionary

lap

noun
/læp/
 
 
1 [usually singular] the top part of your legs that forms a flat surface when you are sitting downThere's only one seat so you'll have to sit on my lap.She sat with her hands in her lap.2 one trip from the beginning to the end of a track used for running, a lane used for swimming, etc.the fastest lap on recordShe has completed six laps.Two people passed him on the final lap.to do a victory lap (= go around the track again to celebrate winning)3 a section of a trip, or of a piece of work, etc.They're off on the first lap of their round-the-world tour.We're almost finished with this proposal. We're on the last lap now.IDIOMS

drop/dump something in someone's lap

(informal) to make something the responsibility of another personThey dropped the problem back in my lap.drop in lapdump in lap

something drops/falls into someone's lap

somebody has the opportunity to do something pleasant without having to make any effort
My dream job just fell into my lap.drops into lapfalls into lap

in the lap of luxury

in easy, comfortable conditions, and enjoying the advantages of being rich
We spent two weeks in the hotel living in the lap of luxury.in the lap of luxury