Fill

The execution of your order. The price you get, which is not always the price you saw.

Where this comes up

Lessons that use the term in context, which is usually more useful than the definition on its own.

Gaps, and what fills them — Empty space on a chart, and the three kinds of it.
What costs really take — Brokerage, STT, slippage and impact, added up honestly.
A journal that is worth keeping — What to record so that it changes behaviour.