A careless fling? (4)

I believe the answer is:

toss

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'fling?' is the definition.
(I know that toss is a more specific form of fling)

I don't understand the remainder of the clue.

Can you help me to learn more?

(Other definitions for toss that I've seen before include "not given by one who doesn't care" , "Fall from horse" , "Throw into the air" , "Careless not to give this" , "Flip in the air, sald or coin" .)

I've seen this clue in the Evening Standard.

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