Sugar that dissolves into water so it becomes a part of it is an example of something that is soluble.
A simple math problem like 2+2 that you can easily find the answer to is an example of something that is soluble.
Origin of soluble
- Middle English from Old French from Late Latin solūbilis from Latin solvere to loosen leu- in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition
- From Middle French soluble.