Popular sample I ultimately dismissed as tasteless (7)
I believe the answer is:
insipid
'tasteless' is the definition.
(similar in meaning)
'popular sample i ultimately dismissed' is the wordplay.
'popular' becomes 'in' ('in' can mean trendy).
'sample' becomes 'sip' (I've seen this in another clue).
'ultimately' says to take the final letters.
The last letter of 'dismissed' is 'd'.
'in'+'sip'+'i'+'d'='INSIPID'
'as' acts as a link.
(Other definitions for insipid that I've seen before include "Colourless" , "Lacking taste or flavour" , "Wishy-washy" , "Tasteless" , "dry" .)