At initial hop, also readily available (2,4)
I believe the answer is:
at hand
'readily available' is the definition.
(I've seen this in another clue)
'at initial hop also' is the wordplay.
'initial' says to take the initial letters.
'also' becomes 'and' (both can mean in addition).
The initial letter of 'hop' is 'h'.
'at'+'h'+'and'='AT HAND'
(Other definitions for at hand that I've seen before include "Close or nearby - just reach" , "Like a neighbour" , "Readily accessible" , "Available nearby" , "Imminent" .)