Pensioners yelled animatedly across river (7)
I believe the answer is:
elderly
'pensioners' is the definition.
(thesaurus)
'yelled animatedly across river' is the wordplay.
I cannot quite see how this works, but
'river' could be 'r' (abbreviation) and 'r' is present in the answer.
an anagram of 'yelled' is 'eldely' which is present in the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for elderly that I've seen before include "Aged" , "Mature" , "Quite old" , "Old or ageing" , "Not young" .)