Worker takes girl up on feeler (7)
I believe the answer is:
antenna
'feeler' is the definition.
(I know that feeler can be written as antenna)
'worker takes girl up' is the wordplay.
'worker' becomes 'ant' (worker is a type of ant).
'takes' says to put letters next to each other.
'girl' becomes 'anne' (girl's name).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'anne' back-to-front is 'enna'.
'ant'+'enna'='ANTENNA'
'on' is the link.
(Other definitions for antenna that I've seen before include "Insect's sensory appendage" , "connected to 41?" , "Transmitting aerial" , "sensitive feeler" , "What detects signals" .)