A girl in New York takes speed (5)
I believe the answer is:
nymph
'a girl' is the definition.
'new york takes speed' is the wordplay.
'new york' becomes 'ny'.
'takes' means one lot of letters go next to another.
'speed' becomes 'mph' (miles per hour).
'ny'+'mph'='NYMPH'
'in' is the link.
(Other definitions for nymph that I've seen before include "Immature form of an insect" , "eg Dryad" , "Beautiful female" , "Young girl - insect" , "Sprite" .)