Enter fashionable place (5)
I believe the answer is:
input
'enter' is the definition.
(I know that input is a more specific form of the action enter)
'fashionable place' is the wordplay.
'fashionable' becomes 'in' (in can mean fashionable or trendy).
'place' becomes 'put' (synonyms).
'in'+'put'='INPUT'
(Other definitions for input that I've seen before include "Feed data into a computer" , "Data contributed" , "Contribution - data fed to computer" , "Person's contribution (to a project)" , "Contribution; enter (data)" .)