Derelict train terminal sheltering onset of bus network (6)
I believe the answer is:
hobnob
'derelict train' is the definition.
The definition suggests a verb in its base form which matches the answer.
'terminal sheltering onset of bus network' is the wordplay.
'terminal' becomes 'hob' (I can't explain this - if you can you should believe this answer much more).
'sheltering' means one lot of letters goes inside another.
'onset' says to take the initial letters (I've seen 'onset of' mean this).
The initial letters of 'of bus network' is 'obn'.
'hob' enclosing 'obn' is 'HOBNOB'.
Can you help me to learn more?
(Other definitions for hobnob that I've seen before include "Socialize, spend time with" , "Fraternise, mingle" , "Spend time together, socialise" , "Spend friendly time together" , "Socialise (especially with posher people)" .)