What a Veer Is
A Veer is undetected drift from intended behavior. It is the difference between where the agent thinks it is and where it actually is — and the critical word is "undetected." An error that is caught is an Obstruction. An error that is not caught is a Veer.
Veers are the most expensive failure mode in AI-native operations because they compound silently. An agent that gradually changes its tone, slowly expands its scope, or quietly starts producing lower-quality output is not failing visibly. It is Veering. By the time the drift is noticed, every output produced since the Veer began is suspect.
The cartographic metaphor is precise. A ship that veers off course by one degree will miss its destination by miles — but the crew will not notice until they look at the map. The Veer is not the error. The Veer is the gap between when the error starts and when someone detects it.