Gazing without seeing a lot of horses (6)
I believe the answer is:
string
'lot of horses' is the definition.
'string' can be an answer for 'horses' (I've seen this before). I am not sure about the 'lot of' bit.
'gazing without seeing a' is the wordplay.
'gazing' becomes 'staring' ('stare' can be a synonym of 'gaze').
'without' suggests deleting specific letters.
'seeing a' becomes 'a'.
'staring' with 'a' removed is 'STRING'.
Can you help me to learn more?
(Other definitions for string that I've seen before include "Hard to say how long a piece of it is" , "tier" , "Group of racers" , "It's difficult to say how long a piece of it is" , "A lightweight cord" .)