Mislaid one's watch and was held up? (4,4)
I believe the answer is:
lost time
'was held up?' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'mislaid one's watch' is the wordplay.
'mislaid' becomes 'lost' ('lose' can be a synonym of 'mislay').
'one's watch' becomes 'time' (I can't justify this - if you can you should give a lot more credence to this answer).
'lost'+'time'='LOST TIME'
'and' is the link.
Can you help me to learn more?
(Other definitions for lost time that I've seen before include "Searching for this, Marcel" , "fell behind" .)