Crowded and comparatively friendly (6)
I believe the answer is:
aswarm
'crowded' is the definition.
(I've seen this before)
'comparatively friendly' is the wordplay.
'comparatively' becomes 'as' (I am not sure about this - if you are sure you should believe this answer much more).
'friendly' becomes 'warm' (associated in meaning).
'as'+'warm'='ASWARM'
'and' is the link.
Can you help me to learn more?
(Other definitions for aswarm that I've seen before include "Teeming" , "Like bees often are" , "crowds everywhere" , "Crawling" , "Crowded" .)