Honour East German city backing end of coal energy (7)
I believe the answer is:
ennoble
'honour' is the definition.
(I know that ennoble is a type of honour)
'east german city backing end of coal energy' is the wordplay.
'east' becomes 'e' (synonyms).
'german city' becomes 'Bonn' (city in Germany).
'backing' shows that the letters should be reversed in order.
'end of' says to take the final letters.
'energy' becomes 'e' (physics symbol as in E=mc2).
The final letter of 'coal' is 'l'.
'bonn' in reverse letter order is 'nnob'.
'e'+'nnob'+'l'+'e'='ENNOBLE'
(Other definitions for ennoble that I've seen before include "Elevate in rank" , "Glorify - raise to the peerage" , "Make a peer" , "Make a count, perhaps" , "Lend greater dignity to" .)