Call to stop article by multinational medical group (4)
I believe the answer is:
whoa
'call to stop' is the definition.
(I've seen this before)
'article by multinational medical group' is the wordplay.
I cannot quite see how this works, but
'article' could be 'a' (the indefinite article in English) and 'a' is found in the answer.
'medical group' could be 'who' (World Health Organisation) and 'who' is located in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for whoa that I've seen before include "Instruction to a horse to stop" , "Call to stop" , "Hold your horses!" , "Stop! - steady on!" , "Said to stop a horse" .)