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.
The root word of "short" is "short," as it is a basic, primary word and not derived from another word.
not short
A short novel or a long short story.
short - They were short on experience.
petite
trip
'chute
the period