from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Geology A fold in rocks in which the rock layers dip inward from both sides toward the axis.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A concave-upward fold in rock strata
from the GNU version of the Collaborative International Dictionary of English
- n. A synclinal fold.
from The Century Dictionary and Cyclopedia
- n. Same as synclinal.
Back-formation from synclinal.(American Heritage® Dictionary of the English Language, Fourth Edition)
syn- + -cline (Wiktionary)