New shape about right for sentence fragment (6)
I believe the answer is:
phrase
'sentence fragment' is the definition.
(I've seen this in another clue)
'new shape about right' is the wordplay.
'new' indicates anagramming the letters.
'about' is an insertion indicator.
'right' becomes 'r' (common abbreviation).
'shape' is an anagram of 'phase'.
'phase' enclosing 'r' is 'PHRASE'.
'for' acts as a link.
(Other definitions for phrase that I've seen before include "a certain expression" , "Word (in a particular way)" , "Sequence of words" , "Sentence unit" , "Group of words forming part of a sentence" .)