For rugby players, an instance of "bottoms up"? (5)
I believe the answer is:
scrum
'for rugby' is the definition.
The definition and answer can be both acts as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for scrum that I've seen before include "brawl" , "Ruck" , "Rugby set-piece" , "Disorderly crowd" , "riotous struggle" .)