Rocking A-side he includes very tacky (8)
I believe the answer is:
adhesive
'tacky' is the definition.
(I've seen this before)
'rocking a-side he includes very' is the wordplay.
'rocking' indicates anagramming the letters.
'includes' indicates putting letters inside.
'very' becomes 'v' (abbreviation).
'a'+'side'+'he'='asidehe'
'asidehe' with letters rearranged gives 'adhesie'.
'adhesie' placed around 'v' is 'ADHESIVE'.
(Other definitions for adhesive that I've seen before include "It sticks things together" , "Stuff that sticks" , "Glue, gum" , "What a sticker" , "Sticky; glue" .)