(a.) Curved in two directions, like the letter S or the Greek /.
Webster's Revised Unabridged Dictionary
| APA | Webster's. (2011). sigmoidal. Retrieved September 21, 2026, from http://smartdefine.org/sigmoidal/definitions/2061944 |
| Chicago | Webster's. 2011. "sigmoidal" http://smartdefine.org/sigmoidal/definitions/2061944 (accessed September 21, 2026). |
| Harvard | Webster's 2011, sigmoidal, Smart Define, viewed 21 September, 2026, <http://smartdefine.org/sigmoidal/definitions/2061944>. |
| MLA | Webster's. "sigmoidal" 28 May 2011. Web. 21 September 2026. <http://smartdefine.org/sigmoidal/definitions/2061944> |