drill stemdrilling fluiddrilling stringdrinage areadripdrip irrigationdriven point piezometerdriven shoedrivewaydrizzledropdrop down sectiondrop froude numberdrop numberdrop size distributiondrop spillwaydrop structuredrop structure stilling basindrop testdropletdropping curvedroughtdrought enduredrought escapedrought evadedrought indexdrowned measuring weirdrowned out jumpdrowned valleydrumdry adiabatdry adiabatic processdry adiabatic ratedry aggregate size distributiondry airdry bulbdry bulb temperaturedry climatedry farmingdry spelldry wall mortarless stonewalldry washdry yeardryland farmingdualdual bridgedual wall reverse circulationduck feetdunedune stabilization