Showy embellishment lacking note (6)
I believe the answer is:
garish
'showy' is the definition.
(I've seen this before)
'embellishment lacking note' is the wordplay.
'embellishment' becomes 'garnish' (garnish is a kind of embellishment).
'lacking' indicates named letters should be taken away.
'note' becomes 'n' (abbreviation).
'garnish' with 'n' taken away is 'GARISH'.
(Other definitions for garish that I've seen before include "Hag, sir, could be gaudy" , "Colourful in a vulgar manner" , "Gaudy, showy" , "in bright colours" , "Tastelessly bright" .)