in thunder

prep_phrase

in thunder

prep_phrase

1

Idiomatic An intensifier, chiefly used with questions.

At the time, however, I was only peevish, wondering what in thunder went on, for I had been in the place long enough to know that, next to the matron, the clock is the most sacred thing in a hospital.1951, John Wyndham, The Day of the Triffids, Harmondsworth: Penguin Books, published 1954, page 7:

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.