Unsteady elephant transporter accompanying ruler (7)
I believe the answer is:
rocking
'unsteady elephant transporter accompanying ruler' is the definition.
I can't tell whether this definition defines the answer.
'transporter accompanying ruler' is the wordplay.
'transporter' becomes 'roc' (I can't explain this - if you can you should believe this answer much more).
'accompanying' is a charade indicator (letters next to each other).
'ruler' becomes 'king' (king is a kind of ruler).
'roc'+'king'='ROCKING'
Can you help me to learn more?
(Other definitions for rocking that I've seen before include "Oscillating" , "Shocking" , "-- Horse; -- chair" , "Seat with curved supports" , "dancing!" .)