1 the organism's functional role in the community (e.g. TROPHIC LEVEL).  other conditions of the organism's existence, such as preferred temperature, moisture and pH, combining spatial habitat with functional interaction with other species.
birthday(Noun) The anniversary of the day on which someone is born. birthday(Noun) The anniversary of the day on which something is created. birthday(Noun) The date on which someone is born or something is created, more commonly called birthdate or date of birth.
There is a distinction between birthday and birthdate: The former, other than February 29, occurs each year (e.g. January 15), while the latter is the exact date a person was born (e.g., January 15, 2001).