A question to those who have access to the Oxford English Dictionary

I've recently read The Drop and The Damage by Howard Linskey.
I had to read half the book before understanding the meaning of the word DROP; it's a lump sum of money that particular criminal organisation paid to an influent man so that he could bribe the higher ranks of police officers.
No dictionary whatsoever gives a definition that can apply to this particular meaning and I'm clueless as to its origin.
Perhaps in the OED then?
BTW I highly recommend this book, similar to The Godfather but situated in Britain.

I found several online dictionaries which have the definition to which you refer. This definition is almost always one of the last ones given (of MANY meanings for this word).

For example, http://www.merriam-webster.com/dictionary/drop lists the meaning as:

"a place or central depository to which something (as mail, money, or stolen property) is brought for distribution or transmission; also : the act of depositing something at such a place <made the drop>"

I couldn't find anything relating to the origin of this expression, however.

Underworld slang is often ignored by dictionaries - but I think I've heard that usage before. I believe it comes from confusing where the money is being put (a drop) with the money itself. As in:
"Did you make the drop? Good. Wait, he says he didn't get the money? Then where did the drop go?"

Goodgulf

I've certainly heard it, as GG says referring to the leaving of some loot or a secret message, but not to the money itself. There again, I'm not well up on underworld slang

Many thanks to all of you! I belatedly thought of the urban dictionary: a lot of definitions but I found it on the second page:
a place where mob money is stored, a collection point.

Then there's the spy use of that term. A "drop" is handing off intelligence to a contact. A "dead drop" is you leaving the information in a certain place and not knowing who will pick it up. That way if you're caught you can't even give the name of the person you hand off information to - you can only say "I left under the gazebo" or wherever.

And the way the English language expands and mutates, I have no problem seeing people applying "drop" to what is drop (money, intelligence, etc) as opposed to the act of dropping it or the place where it is dropped. As in "I dropped the drop at the drop".

Goodgulf

I remember we use to call the bank's night safe (a facility at which you clients could deposit cash and cheques after hours) as the "drop box". And it was just that; you opened the lid and dropped a cash bag down a shute.

It is probably derived from the term to 'drop off' something. Meaning to transport something to a particular/ appointed place. I have heard this phrase used as both a verb and a noun. 'The drop of'f is the place where an item is to be delivered... usually in reference to contraband in gangster movies.

Well, well, I'll have learnt a lot thanks to you!

The same with, "I dropped a dime on that creep." (old pay telephone amount still used). "He got the DROP on that guy real quick." "OH! Check that out! That is so BAD dude." All this slang can drive a person bonkers at times. And yes, "We just intercepted that call, and they're going to make the DROP at the old windmill." Usually a kidnapping case.