Undemanding, effortless (4)
I believe the answer is:
easy
This clue is a double definition.
'undemanding' is the first definition.
(associated in meaning)
'effortless' is the second definition.
(associated in meaning)
(Other definitions for easy that I've seen before include "without difficulty" , "for a piece of cake" , "Simple or uncomplicated" , "Not challenging" , "Promiscuous" .)