Dance move at the end of function (5)
I believe the answer is:
tango
'dance' is the definition.
(tango is a type of dance)
'move at the end of function' is the wordplay.
'move' becomes 'go' (to go is to move).
'at the end of' says to put letters next to each other (some letters go at the end of others).
'function' becomes 'tan' (tangent, mathematical function).
'go' put after 'tan' is 'TANGO'.
(Other definitions for tango that I've seen before include "One from Argentina" , "Activity requiring two to" , "Latin American dance takes two to do it" , "Letter T in radio comms" , "South American dance (for two?)" .)