Tell, on getting the tip-off, a girl (4)
I believe the answer is:
ella
'a girl' is the definition.
(girl's name)
'tell on getting the tip' is the wordplay.
'tell on' becomes 'lla' (I am not sure about this - if you are sure you should believe this answer much more).
'getting' says to put letters next to each other.
'tip' indicates one should take the final letters (one tip of the word).
The last letter of 'the' is 'e'.
'lla' put after 'e' is 'ELLA'.
'off' is the link.
Can you help me to learn more?
(Other definitions for ella that I've seen before include "Ms Fitzgerald" , "- - Fitzgerald (mus.)" , "Woman" , "Great late jazz singer . . . . Fitzgerald" , "Girl" .)