metastyle

from The Century Dictionary.

• noun In botany, an unusually long style: said chiefly of trimorphic plants. Compare mesostyle and parastyle.
• noun The posterior enamel-covered ridge on the outer side of such a molar as that of a horse: correlative with parastyle and mesostyle.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun botany A very long style
• noun dentistry A ridge, covered with enamel, on the outer side of a molar tooth in animals such as the horse