- to extend partly under.
Origin of underlap
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for underlap
In many cases, it is advisable to have an underlap of the material.
The placket of a skirt should have an underlap extending well below the opening.
On the left side of the skirt sew an underlap of sufficient length to extend well below the end of the opening.
This is the type most likely either to overlap or underlap, depending upon the prison rgime and the after-parole circumstance.Criminal Types
V. M. Masten