0 not enough or not strong enough:
2 of little value or importance, or not being strong, solid, or large:
The industry that we are discussing is not an insubstantial industry.
In a full year they would cost £440 million—not an insubstantial sum.
When they are asked upon what data they have come to their conclusions, it is found that the data is often insubstantial.
He knows it was no insubstantial contribution that was made in that way.
I can understand that, as we now know how insubstantial was the basis on which the figures were produced.
We would perhaps like things to move more quickly, but it is not an insubstantial grant.
The higher estimate is not insubstantial.
The information gathered was insubstantial.
