Definitions

1. noun

A fold in the Earth’s crust, typically formed by compression, in which the strata slope inward from both sides, forming a concave shape.

“The geologists studied the syncline in the rock formation to understand its tectonic history.”

2. noun

A fold or bend in something, especially a book or a sheet of paper.

“The syncline in the sheet of paper made it difficult to read the text.”