FAILURE 
It has been about three months, maybe more, since I failed to complete the puzzle correctly --- so I guss I was due. I did not know LEMMA (which I should have) or what crossed it, IMS. What are IMS?
Dull ending? ARD [I'd go with "dull finish"]
Business issue since 1917 FORBES [I was thinking unions, etc.]
Bargain hunters' mecca TAG SALE [a mecca is a place; a sale is an event at a place]
