snellen chart in Medicine Expand. Snellen chart SnelÂ·len chart (snÄl'Én) n. A chart for testing visual acuity, usually consisting of letters, numbers, or pictures printed in lines of decreasing size which a patient is asked to read or identify at a fixed distance.
Vanilla is a flavor derived from orchids of the genus Vanilla, primarily from the Mexican species, flat-leaved vanilla (V. planifolia). The word vanilla, derived from the diminutive of the Spanish word vaina (vaina itself meaning sheath or pod), translates simply as little pod.
âImitation vanilla is manufactured either from clove oil (eugenol) or as a breakdown product of lignin from a conifer (e.g., spruce, Picea).â.