undercross
nounUK /ˈʌndərˌkrɒs/ · US /ˈʌndərˌkrɔs/
Etymology From under- + cross.
1
Engineering, Natural sciences, Physical sciences A passage or underpass where a roadway, railway, or infrastructure crosses under another.
- The whole of the undercross is perfect, excepting the bases of the outer columns, and forms a fine superstructure of gigantic support to the light and delicate parts above.1800 December, “Description of St Stephen's Chapel”, in THE SCOTS MAGAZINE, volume 62, APPENDIX 1800., page 857:
2
Mathematics, Sciences, Topology The strand or segment in a knot diagram that passes beneath another at a crossing; i.e., the under‑crossing strand in a knot projection. As distinguished from the overcrossing or over‑strand in knot projections
- If we arrive at an undercross, then we move the branch of the overcross over the rest of the knot up to the end of K.2023 January 4, Thomas Fiedler, One-cocycles And Knot Invariants, World Scientific Publishing Company, page 52:
- Synonyms
- undercrossing, underpass
- Antonyms
- overcrossing