Walked in for an introduction (4)
I believe the answer is:
trod
'walked' is the definition.
(treading is a kind of walking)
'in for an introduction' is the wordplay.
'in' says the answer is hidden in the clue.
'TROD' can be found hidden inside 'for introduction'.
(Other definitions for trod that I've seen before include "Pressed (grapes) by foot" , "Took steps" , "Walked upon" , "Crushed (grapes) by foot" , "Stepped heavily" .)