Move slowly — after first count another count comes up (5)
I believe the answer is:
creep
'move slowly' is the definition.
(I've seen this before)
'after first count another count comes up' is the wordplay.
'after' says to put letters next to each other.
'first count' becomes 'c' (pst letter of 'count').
'another count' becomes 'peer' (I am not sure about this - if you are sure you should believe this answer much more).
'comes up' shows that the letters should be reversed in order.
'peer' reversed gives 'reep'.
'c' put next to 'reep' is 'CREEP'.
Can you help me to learn more?
(Other definitions for creep that I've seen before include "Move stealthily or along the ground" , "worm" , "Steal" , "Move silently and secretly" , "Move furtively" .)