Highball! (3)
I believe the answer is:
lob
'highball' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
This is the entire clue.
Can you help me to learn more?
(Other definitions for lob that I've seen before include "High throw or hit" , "Throw ball in high arc" , "Lofted ball" , "Chuck" , "High shot" .)