In general, it takes a long time (3)
I believe the answer is:
era
'a long time' is the definition.
(a long period of time)
'in general it' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ERA' is hidden in the letters of 'general it'.
'takes' acts as a link.
(Other definitions for era that I've seen before include "Stage" , "Age of importance" , "Series of years" , "Important historical period" , "Important time" .)