Referring something which is not the last item, but one before the last one

Solution 1:

It's not a phrase, but the name for an item which is next to last (in a list, or in an order) is penultimate. And although you didn't ask, the name for the item which is next to the next to the last is antepenultimate.

Solution 2:

More casual than penultimate is second last, second to last, or second-to-last.

I did some queries in the COCA and BNC corpora, and it seems that second last is the more common form in British English. Second to last / second-to-last are more common in American English.

Solution 3:

Another option is 'last but one' (for penultimate), and 'last but two' (for antepenultimate). Casually, I would say 'second last' (I speak a kind of British English), so it confirms what dangph said. I am also told Americans say 'the next to last'.