Swear at dogs on top of Everest (5)
I believe the answer is:
curse
'swear at' is the definition.
(thesaurus)
'dogs on top of everest' is the wordplay.
'dogs' becomes 'curs' (cur is a kind of dog).
'on top of' suggests taking the first letters (I've seen 'on top' mean this).
The first letter of 'everest' is 'e'.
'curs'+'e'='CURSE'
(Other definitions for curse that I've seen before include "Anathema" , "Cause of harm or misery" , "Swear - oath" , "Invoke evil upon" , "Blaspheme; damn" .)