Plain English Meaning
Flying so slowly and with the nose so high that the airplane is sinking quickly, the controls feel mushy, and the wing is barely doing its job. It is not a full stall, but it is close to one.
Full Definition
A flight condition in which the airplane is flown at a high angle of attack near the stall, producing a high rate of descent with sluggish, partially effective controls, while the wing is still generating some lift but not enough to maintain altitude. The airplane is not fully stalled but is no longer flying cleanly through the air.
Context Anchor
Seen in slow flight, descent, approach, and stall-recovery discussions, especially when tries to the nose up instead of letting the airplane regain .