Temporarily secures what's said to be an obligation (5)
I believe the answer is:
tacks
'temporarily secures' is the definition.
'tacks' can be an answer for 'secures' (tacking is a kind of securing). I am not sure about the 'temporarily' bit.
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for tacks that I've seen before include "Changes course" , "They secure" , "Approaches" , "Shorts nails with big heads" , "Drawing pins" .)