to lead those who cannot lead themselves: to conduct, guide, and provide for the dependent
This is a small word that carries some of the Bible's most tender pictures of care. At its core it simply means to lead or conduct someone, but its objects across Scripture are almost always the weak and the helpless: children, nursing animals, wounded captives, a people who cannot find their own way. So the leading is never brisk or impersonal. It is the leading of one who takes responsibility for the pace and the needs of those being led.
Scholars debate whether the gentleness and the water that so often surround this word are built into the word itself or come from the company it keeps. The older view read it as meaning specifically to lead to a watering place and let rest there, drawing on an Arabic relative. Most modern study has stepped back from that, pointing to a passage where a drunken city has no one to lead her, with no flock and no water anywhere in sight (Isaiah 51:18). There the bare meaning is just to lead, to take by the hand.
The honest picture is that the word means to lead, while its setting again and again supplies the tenderness. Out of its ten or so appearances, all but one sit among shepherds, flocks, springs, or vulnerable travelers. That is why generations of readers have heard such warmth in it, and why a fair summary is leading with care.
One use stretches the same idea to providing rather than walking: Joseph sustaining Egypt with bread (Genesis 47:17). The thread that holds the range together is taking charge of the dependent and seeing them through.