Male in truth that is the type to exude charm (8)
I believe the answer is:
smoothie
'the type to exude charm' is the definition.
'male in truth that is' is the wordplay.
'male' becomes 'm' (common abbreviation).
'in' means one lot of letters goes inside another.
'truth' becomes 'sooth' ('sooth' can be a synonym of 'truth').
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is').
'm' going within 'sooth' is 'smooth'.
'smooth'+'ie'='SMOOTHIE'
(Other definitions for smoothie that I've seen before include "Thick fruity drink - charmer" , "Glib speaker" , "cold and thick" , "Smarmy type" , "Fruit pured with milk" .)