Yell and clap (7)
I believe the answer is:
thunder
I believe this clue is a double definition.
'yell' is the first definition.
(thesaurus)
'clap' is the second definition.
(thesaurus)
'and' is the link.
(Other definitions for thunder that I've seen before include "Clap" , "Speak in booming voice" , "What comes with lightning" , "Speak loudly and forcefully" , "Loud rumbling noise" .)