This suggests lob used for tennis - or pairs of across answers here? (5,7)
I believe the answer is:
mixed doubles
'pairs of across answers here?' is the definition.
The definition suggests a plural noun which matches the answer.
'this suggests lob used for tennis' is the wordplay.
I cannot really see how this works, but
'tennis' could be 'doubles' (doubles is a kind of tennis) and 'doubles' is present in the answer.
The remaining letters 'mixed' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'or' acts as a link.
Can you help me to learn more?
(Other definitions for mixed doubles that I've seen before include "shorts?" , "Range of big shots" , "His 'n' hers tennis" , "tennis match?" , "Woman/man v woman/man at tennis" .)