Not progressing and developing as fast as others, as in economic and social aspects
She hurriedly ascended the narrow dimly lit stone staircase, calling to Pierre, who was lagging behind, to follow.
I'm sure Mr. Dean doesn't want to wait up for an out-of-shape old lady lagging behind him.
Jim hastened his lagging steps at this assurance of a quick relief from the dark passage.
Taran reached the lagging man and hacked him down, leapt over the body and one of the snapping traps, and continued.
by taking advantage of this lagging that thermal treatment causes such wonderful changes in the properties of the cold metal.