Definition of "stressor"

These children are constitutionally sad. Other children, like Luke, develop depressive feelings out of the blue or in response to some mild stressor.

1997, Edward M. Hallowell, When You Worry About the Child You Love, page 162

These paradoxical pleasures […] are acquired by controlling one's exposure to the stressor in gradually increasing doses.

2011, Steven Pinker, The Better Angels of Our Nature, Penguin, published 2012, page 670

Plenty of people see hosting a large group as a stressor.

2023 May 1, Reem Kassis, “What Home Cooking Does That Restaurants Can’t”, in The Atlantic‎