undertow, under, underdetermined blind source separation, undersecretary for international affairs, Underlying socket stream context options, underdetermined blind sources separation, Underpants.Often used in the plural., underhand drift cut-and-fill stoping, Underflow interception water source site, underprivileged sections of the community, underfloor air distribution system plenum, under-cover-reverse-building method 返回 undercroft