To droop one's head (as when shy, sleepy, sad, drunk, etc.).
The head is implied and therefore pa- caus. or -an are seldom used.
Wā ya patukku' maglinduhan anak na.
He is always drooping his head in mourning for his child.
My older brother has drooped his head because he is sleepy.
If you say lay in the above sentence then his head is still drooped. If you remove the lay his head is in the process of drooping. If bay then his head is no longer drooped.