Continuously updated · AI Dictionary
The language of AI,
clearly defined.
A field guide to the words changing how we build, work and think—from token and transformer to AI agents and vibe coding.
522 terms
10 topics
1847–2026 timeline
Built as a living reference
Clear words. Useful context.
01
Plain English firstThe definition comes before the jargon.
02
Usage over hypeEstablished meanings are separated from new or informal ones.
03
Show the trailSources appear on entries as they are reviewed.
Latest update · October 2026
New in the AI Dictionary
Fresh language for the newest shifts in AI, explained without the jargon.
proactive agent
an AI agent that uses context, events, or inferred user needs to decide when to offer help or initiate authorized work without waiting for a new explicit request for each intervention
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guardian agent
an AI-based supervisory system or agent that monitors other AI agents and helps keep their actions within defined goals, permissions, policies, and safety boundaries, for example by investigating behavior, requesting approval, or triggering containment
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surrogate model
a model used as a computationally cheaper approximation of another model, simulation, or process; in AI-based scientific and engineering workflows, it is often trained on examples to predict results that would otherwise require expensive calculations or experiments
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world action model
an AI model for embodied control that couples learned representations or predictions of how the world changes with the generation of actions, so that expected physical outcomes help determine what a robot should do
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