Stick heard to shatter and echo (6)
I believe the answer is:
adhere
'stick' is the definition.
(I know that stick can be written as adhere)
'heard to shatter and echo' is the wordplay.
'to shatter' is an anagram indicator (I've seen 'shattered' mean this).
'and' means one lot of letters go next to another.
'echo' becomes 'e' (phonetic alphabet: alpha, bravo, charlie etc.).
'heard' with letters rearranged gives 'adher'.
'adher'+'e'='ADHERE'
(Other definitions for adhere that I've seen before include "Stay attached" , "Cling, attach" , "Stick fast (to something)" , "Stick or cleave to" , "Stick L" .)