Tongue-lashing's starting at batting (5)
I believe the answer is:
latin
'tongue' is the definition.
(Latin is an example)
'lashing's starting at batting' is the wordplay.
'starting' suggests taking the first letters.
'batting' becomes 'in' (as in batting or being 'in' in cricket).
The first letter of 'lashings' is 'l'.
'l'+'at'+'in'='LATIN'
(Other definitions for latin that I've seen before include "Learning it 'an honour' (Churchill)" , "Cicero's tongue" , "Language of old Romans" , "Old Roman language" , "A Romance language" .)