SOS, Ed lost prescriptions (5)
I believe the answer is:
'prescriptions' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Perhaps you can see a link between them that I can't see?
'sos ed lost' is the wordplay.
'lost' indicates anagramming the letters.
'sosed' anagrammed gives 'DOSES'.
Can you help me to learn more?
(Other definitions for doses that I've seen before include "Prescribed amounts of medicine" , "Quanitites of medicine" , "Administers medicine to (someone)" , "Prescribed quantities of medicine" , "Potion portions" .)