The 2 x 2 square is formed by the last two letters of 17 A, the third in 5 D, and the first in 14 A. Although 14 is unclued, the other three letters and the title of the crossword should make it obvious.
I found online searching to be far more useful than Brewers.
I started to get the unclueds when I realised a theme-related connection between possible answers for 24a and 38a and that immediately gave the theme word.