One following joke with poke of tongue (7)
I believe the answer is:
punjabi
'tongue' is the definition.
(Punjabi is an example)
'one following joke with poke' is the wordplay.
'one' becomes 'i' (Roman numeral).
'following' means one lot of letters go next to another.
'joke' becomes 'pun' (pun is a type of joke).
'with' means one lot of letters go next to another.
'poke' becomes 'jab' (synonyms).
'pun'+'jab'='punjab'
'i' put after 'punjab' is 'PUNJABI'.
'of' acts as a link.
(Other definitions for punjabi that I've seen before include "From a state in Northwest India" , "Eastern language" , "tongue" , "talk of Amritsar?" , "Possibly Pakistani" .)