Lady of the house was out to lunch in the morning (5)
I believe the answer is:
madam
'lady of the house' is the definition.
(I've seen this in another clue)
'out to lunch in the morning' is the wordplay.
'out to lunch' becomes 'mad'.
'in the morning' becomes 'am' (AM on a clock).
'mad'+'am'='MADAM'
'was' is the link.
(Other definitions for madam that I've seen before include "'Call Me ---' (I. Berlin)" , "Courteous form of address to a woman" , "pompous young lady?" , "Conceited girl (colloq.)" , "Woman of standing" .)