Definition of «early onset»

"Early onset" is a term borrowed from medical vocabulary that is used colloquially and often hyperbolically to describe the premature appearance of a condition or behavior. In internet slang, it is frequently used in a dark or self-deprecating humorous way to exaggerate one's physical or mental state. It suggests that the speaker feels much older or more decrepit than they actually are due to stress or exhaustion. The tone is usually ironic, using clinical language to describe everyday feelings of tiredness or stiffness.