Bombay duck
Concise Oxford English Dictionary © 2008 Oxford University Press:
Bombay duck/bɒmbeɪˈdʌk/
▶noun the bummalo (fish), dried and eaten as an accompaniment to curries.
– origin C19: alt. of bummalo by assoc. with the city of Bombay in India, from which bummalo were exported; the reason for the use of the term duck is unknown.
'Bombay duck' also found in these Oxford entries:

