According to Mayo Clinic, Down syndrome causes a distinct facial appearance, intellectual disability, developmental delays, and may be associated with thyroid or heart disease in a person. So calling people with this syndrome 'Mongoloid' is extremely vulgar and disrespectful to ethnic Mongolians. Likewise, how will the population react if Down Syndrome was associated with 'European' looks? If you use this term, you are automatically a xenophobic, in my opinion.
If any difference is noteworthy, it would probably be that an age is usually between two times, e.g. 1290-1450AD, whereas an era is less set - but that isn't a rule, its just a matter of usage. Synonyms would be epoch, or eon. Source(s):
What is the Difference between Summer, Winter, Autumn and Spring Seasons. Technically speaking; season is the division of years in different parts. It usually marks changes in weather conditions and daylight hours. In different seasons intensity of sun rays reached to the surface of earth, changes.pring is a transitory season between winter and summer. The length of days and nights is almost equal in this season. Spring has very short duration, usually three to four weeks. Spring season is marked with the flower blooms and appearance of new leaves on the trees.