Tango on fellow's bed (3)
I believe the answer is:
cot
'bed' is the definition.
(cot is a type of bed)
'tango on fellow's' is the wordplay.
'tango' becomes 'T' (phonetic alphabet: alpha, bravo, charlie etc.).
'on' says to put letters next to each other.
'fellow' becomes 'co' (eg a co-worker is a fellow worker).
't' put after 'co' is 'COT'.
(Other definitions for cot that I've seen before include "Function" , "Baby bed" , "Small child's bed" , "Small boat to hold a baby" , "Infant's bed" .)