For a while can be used to mean 'for a short period of time'.
After a short period you can take another test in 2 weeks.
Another word could be era.
short manner
One word that usually means "not short" is tall. The other major antonym is long.
short is a rootword. examples: shortage, shorter, shorten
not short
short - They were short on experience.
A short novel or a long short story.
petite
trip
the period
AGE.