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.
Vanilla sex is what a culture regards as standard or conventional sexual behaviour. Different cultures, subcultures and individuals have different ideas about what constitutes this type of sex. Often, it is interpreted as sex which does not involve such elements as BDSM, kink, or fetish activities.