Half of guests not turning up at first - rudely, one could be put out (6)
I believe the answer is:
tongue
'up at first rudely one could be put out' is the definition.
I can't tell whether this defines the answer.
'half of guests not turning' is the wordplay.
'half of' means to take half the letters.
'turning' indicates an anagram.
'guests' halved is 'gue'.
'gue'+'not'='guenot'
'guenot' is an anagram of 'TONGUE'.
Can you help me to learn more?
(Other definitions for tongue that I've seen before include "Speech" , "Mouth organ; language" , "spit" , "Organ of taste" , "Go tune up what's in the mouth" .)