Attention deficit hyperactivity disorder (ADHD) should be diagnosed and treated in children as young as age 4, according to new guidelines from the American Academy of Pediatrics. Skip to main content
ephemeris. 1  a table showing the positions of a heavenly body on a number of dates in a regular sequence. 2  an astronomical almanac containing such tables. 3  Archaic. an almanac or calendar.
ephemeral (comparative more ephemeral, superlative most ephemeral) 1  Lasting for a short period of time. ( 2 biology) Existing for only one day, as with some flowers, insects, and diseases. ( 3 geology, of a body of water) Usually dry, but filling with water for brief periods during and after precipitation.