Full Definition of AUTISM. : a variable developmental disorder that appears by age three and is characterized by impairment of the ability to form normal social relationships, by impairment of the ability to communicate with others, and by stereotyped behavior patterns.â auÂ·tisÂ·tic \oÌ-Ëtis-tik\ adjective or noun. a variable developmental disorder that appears by age three and is characterized by impairment of the ability to form normal social relationships, by impairment of the ability to communicate with others, and by stereotyped behavior patterns.
Other organizations have established a variety of alternative definitions for their standard reference conditions. In chemistry, IUPAC has established two standards: standard temperature and pressure (STP) as a temperature of 273.15 K (0 Â°C, 32 Â°F) and an absolute pressure of exactly 100 kPa (1 bar).
Tips & Warnings. 1  Though the standard for normal body temperature is 98.6 degrees Fahrenheit, temperature varies by person, age, level of activity and time of day. 2  Any major variance in body temperature that lasts more than a few days, especially a fever, needs to be checked out by a doctor.