Tasteless, insipid (5)
I believe the answer is:
bland
I believe this is a double definition.
'tasteless' is the first definition.
(associated in meaning)
'insipid' is the second definition.
(synonyms)
(Other definitions for bland that I've seen before include "Insipid - uninteresting" , "Mild and insipid" , "Boring" , "Unruffled but unstimulating" , "Mild; dull" .)