The opposite could be temporary, interim, or brief.
Brief, concise.
The opposite of a prolonged activity is a brief one. Spending the summer in a place could have the opposite "a brief visit." The opposite of engaging in the same activity all summer would be doing many and varied things.
In length, the opposite of long is short. In time, the opposite of long may be short or brief.
The opposite of enduring (lasting) is ephemeral, brief, or fleeting. The opposite of the verb enduring (persevering) is surrendering, giving up, or quitting.
Lenghty
The opposite could be temporary, interim, or brief.
Lengthy, long...
Brief, concise.
In length, the opposite of long is short. In time, the opposite of long may be short or brief.
The opposite of a prolonged activity is a brief one. Spending the summer in a place could have the opposite "a brief visit." The opposite of engaging in the same activity all summer would be doing many and varied things.
brief in a hurry limited time a little while a brief time
For dimensions, either tall or long depending on what you are describing.For time, the opposite of short (brief) would be long or lengthy.
In length, the opposite of long is short. In time, the opposite of long may be short or brief.
The opposite of enduring (lasting) is ephemeral, brief, or fleeting. The opposite of the verb enduring (persevering) is surrendering, giving up, or quitting.
The sentence was brief.He looked at her for a brief moment.
Your question was brief.