You and I take time for an application (5)
I believe the answer is:
usage
'an application' is the definition.
(I've seen this before)
'you and i take time' is the wordplay.
'you and i' becomes 'us'.
'take' means one lot of letters go next to another.
'time' becomes 'age' (an age is a period of time).
'us'+'age'='USAGE'
'for' is the link.
(Other definitions for usage that I've seen before include "Usual practice" , "Interest of old" , "Accepted or habitual practice" , "Customary way in which language is spoken or written" , "Style of language" .)