| contaminant | An impurity; any material of an extraneous nature associated with a chemical, a pharmaceutical preparation, a physiologic principle, or an infectious agent. (05 Mar 2000) |
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| journal article | The predominant publication type for articles and other items indexed for nlm databases. (12 Dec 1998) |
| wetland hydrology | <ecology> In general terms, permanent or periodic inundation or prolonged soil saturation sufficient to create anaerobic conditions in the soil. (09 Oct 1997) |
| hydrology | <study> The science of water, its properties, phenomena, and distribution over the earth's surface. Origin: Hydro-, 1: cf. F. Hydrologie Source: Websters Dictionary (01 Mar 1998) |