whether one likes it or not; without choice; willy-nilly
Expresses that something happens regardless of one's will; often used when a situation forces an outcome.
I was forced to take on that job whether I liked it or not.
The match was called off willy-nilly due to heavy rain.
有無を言わさず is a stronger, more forceful expression meaning 'without giving a chance to say yes or no', often used in authoritative contexts.
Standard kanji spelling.
Variant with 無く instead of なく.
From 否 (いや, 'no') + 応 (おう, 'yes') + なく (adverbial form of ない), literally 'without yes or no'.