In civil engineering, the words invert and obvert are used in the context of pipe elevations. I gather that invert means: interior bottom elevation of pipe, and obvert means: interior top elevation of pipe.
However, using the word invert in this context seems strange to me. To me, none of these definitions fit:
- a: to reverse in position, order, or relationship
b: to subject to inversion
- a: to turn inside out or upside down
b: to turn inward
- a: to find the mathematical reciprocal of
b: to divide using fractions, invert the divisor and multiply
What does the word invert have to do with pipes? What has been inverted?