Origin: Germanic Old English prefix
Outbreak has 3 different meanings across 1 category:
An eruption; the sudden appearance of a rash, disease, etc.
"The sudden outbreak of measles spread quickly through the school before it was contained."
In plain English: An outbreak is when something bad, like an illness or violence, suddenly starts happening to many people at once.
"The sudden outbreak of flu caused many students to stay home from school."
Usage: Use "outbreak" to describe the sudden start or spread of an epidemic, war, or violent incident rather than referring to the total number of cases involved. It specifically marks the beginning phase where symptoms first appear and begin to increase rapidly in frequency.
To burst out.
"The pressure in the pipe was so great that it caused a sudden outbreak of steam into the kitchen."
From Middle English outbreken, oute-breken, from Old English ūtābrecan ("to break out"), equivalent to out- + break. Cognate with Saterland Frisian uutbreeke ("to break out, burst out"), West Frisian útbrekke ("to break out"), Dutch uitbreken ("to break out, burst out"), German ausbrechen ("to break out, erupt").