Relating to a situation where there are only two possible outcomes, either complete success or total failure, with no middle ground. Her all-or-nothing approach to negotiations often led to high stakes outcomes.
Describing a mindset or attitude that is uncompromising and demands total commitment or effort. His all-or-nothing attitude towards his fitness goals meant he either worked out intensely or not at all.
Occurring completely or not at all; characteristic of a response that either happens in full or does not happen, especially in physiological contexts. An action potential is an all-or-nothing electrical event in a neuron.