under- /ʌndə $ -dər/ BrE AmE prefix
1 . less of an action or quality than is correct, needed, or desired:
underdevelopment
undercooked cabbage
2 . going under something:
an underpass (=a road or path that goes under another road)
3 . inside or beneath other things:
undergarments
4 . less important or lower in rank:
a head gardener and three under-gardeners