Skip — nothing massive initially to put on it (4)
I believe the answer is:
omit
'skip' is the definition.
(I've seen this before)
'nothing massive initially to put on it' is the wordplay.
'nothing' becomes 'o' (looks like zero - 0).
'initially' suggests taking the first letters.
'to put on' says to put letters next to each other.
The first letter of 'massive' is 'm'.
'o'+'m'+'it'='OMIT'
(Other definitions for omit that I've seen before include "Leave out or fail to do" , "Drop" , "Miss out" , "Fail to include" , "Leave out or exclude" .)