Pretentious, receiving the Queen in this vein? (6)
I believe the answer is:
artery
'this vein?' is the definition.
'pretentious receiving the queen' is the wordplay.
'pretentious' becomes 'arty' ('arty' can be similar in meaning to 'pretentious').
'receiving' indicates putting letters inside.
'the queen' becomes 'er' (Elizabeth Regina).
'arty' going around 'er' is 'ARTERY'.
'in' acts as a link.
(Other definitions for artery that I've seen before include "Principle channel of circulatory system" , "blood line" , "Major (blood) route" , "main line" , "Something that could be clogged" .)