When jogging, a kilt must perform various functions (9)

I believe the answer is:
multitask
'perform various functions' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'when jogging a kilt must' is the wordplay.
'a kilt must' anagrams to 'MULTITASK'.
However, I'm not sure how this is indicated.
Can you help me to learn more?
(Other definitions for multitask that I've seen before include "To perform several jobs" , "Do things simultaneously" , "execute jobs simultaneously" .)
