HD Glossary

Note: Some words can have differing definitions depending on the context in which they are used. The definitions presented here are the ones that best apply to the words as they are used. HDSA is grateful to the Stanford Hopes website for their contribution and maintenance of this glossary.



  • warfarin - A drug taken by mouth to prevent blood clotting. Studies have shown that taking warfarin in combination with aspirin could lead to excessive bleeding.
  • water-soluble - Capable of being dissolved in water.
  • wet lab - Refers to experiments performed at the lab bench.
  • white blood cells - Cells that circulate in the blood and lymphatic system and congregate in the lymph glands and spleen. (The lymphatic system consists of the tissues and organs, including the bone marrow, spleen, thymus, and lymph nodes that produce and store cells that fight infection and the network of vessels that carry a fluid called lymph). White blood cells are part of the immune system and are responsible for both directly and indirectly attacking foreign invaders of the body.
  • white matter - The matter in the brain underlying the gray matter which contains a large number of nerve fibers.
  • wild-type - The typical form of an organism or gene as it occurs in nature, as distinguished from mutant forms that may result from selective breeding or disease.