Place flags as quiet welcome (4)
I believe the answer is:
pave
'place flags' is the definition.
(as in paving flagstones)
'quiet welcome' is the wordplay.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'welcome' becomes 'ave' ('welcome' or 'farewell' - from Latin).
'p'+'ave'='PAVE'
'as' acts as a link.
(Other definitions for pave that I've seen before include "Cover with slabs" , "Surface with stone etc." , "Cover with flags" , "Put on a surface of stone slabs" , "Dress with stone etc" .)