A depression or a groove found on the surface of an organ or tissue, as on the surface of the brain separating adjacent convolutions. Large sulci that divide the brain into lobes as well as the two hemispheres are more often called fissures. Plural: sulci. See fissure. calcarine sulcus See calcarine fissure.
Definition of SYNERGIST. : something (as a chemical or a muscle) that enhances the effectiveness of an active agent; broadly: either member of a synergistic pair.ADVERTISEMENT.noun synÂ·erÂ·gist \-jÉst\. something (as a chemical or a muscle) that enhances the effectiveness of an active agent; broadly: either member of a synergistic pair. ADVERTISEMENT.
1 Allergist, a doctor who focuses on diseases and conditions that cause allergic reactions, involve the immune system or asthma. 2  Several migraine symptoms are similar to those experienced by people with allergies, such as head pain, puffy eyelid and hives.