Spike
In plain terms
A time-boxed task to research or reduce uncertainty.
Going deeper
A spike is exploratory work to investigate a question, prototype an approach, or gain knowledge before committing to a solution. It buys information.
Under the hood
Time-boxed to limit investment; output is learning or a prototype, not shippable features.
Examples
Technical research, proof of concept, risk reduction, estimation, prototyping.
Think of it like...
Like a scouting mission to map unknown territory before the main expedition.