Tissue transplant is hard work (5)

I believe the answer is:

graft

I believe this clue is a double definition.

'tissue transplant' is the first definition.
(as in a skin graft)

'is hard work' is the second definition.
(graft can mean working hard)

(Other definitions for graft that I've seen before include "Means of propagation - hard work?" , "Hard work - corrupt profit" , "Hard work; bribery" , "Transfer of tissue - hard work!" , "Hard work - illicit gain" .)

I've seen this clue in The Telegraph and The Times.

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