Definition 1 of 2
Plain English Meaning
It's the first question an instructor asks to get a class discussion going. It's worded so students have to think and explain, not just give a one-word answer.
Full Definition
In a guided discussion, the opening question used by an instructor to introduce a topic and start students thinking and talking about it. A lead-off question is open-ended, calls for an extended response rather than a yes/no answer, and is designed to launch group discussion rather than test recall.
Context Anchor
Seen in flight instructor training when learning how to run a guided discussion instead of simply lecturing.
Derivation
"Lead-off" comes from the idea of leading off, or starting, a sequence — the same usage as the lead-off batter in baseball, who is first in the order. The question that goes first and opens the discussion.