Type "I caught onto the curly tail" (6)
I believe the answer is:
italic
'type' is the definition.
(italic is a kind of type)
'i caught onto the curly tail' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'onto' says to put letters next to each other.
'the curly tail' becomes 'tali' (I am not sure about this - if you are sure you should believe this answer much more).
'c' after 'tali' is 'talic'.
'i'+'talic'='ITALIC'
Can you help me to learn more?
(Other definitions for italic that I've seen before include "kind of signing" , "Letters written sloping to the right" , "Principally it" , "Relating to slanting handwriting or type" , "leaning over" .)