piriformis

English

Alternative forms

• pyriformis

Etymology

Unadapted borrowing from New Latin pirifōrmis, ellipsis of mūsculus pirifōrmis (“pear-shaped muscle”). Doublet of piriform.

Pronunciation

• (Received Pronunciation) IPA^(key): /ˌpɪ.ɹɪˈfɔː.mɪs/
• (General American) IPA^(key): /ˌpɪɹ.əˈfɔɹ.mɪs/

Noun

piriformis (plural piriformes)

1. (anatomy, zootomy) A gluteal muscle which arises from the front of the sacrum and the ischium or sacrotuberous ligament, passes out of the pelvis through the greater sciatic foramen, and inserts into the greater trochanter of the femur, serving in humans to rotate the thigh laterally.

Derived terms

• piriformis syndrome

Translations

muscle that rotates the thigh laterally

• Chinese:

  Mandarin: 梨狀肌／梨状肌 (lízhuàngjī)

• Japanese: 梨状筋 (りじょうきん, rijōkin)

References

• “pyriformis”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.
• “piriformis”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.

Latin

Alternative forms

• pyrifōrmis

Etymology

From pirum (“a pear”) +‎ -fōrmis (“-form, -shaped”, adjectival suffix).

Pronunciation

• (Classical Latin) IPA^(key): /pi.riˈfoːr.mis/, [pɪrɪˈfoːrmɪs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /pi.riˈfor.mis/, [piriˈfɔrmis]

Adjective

pirifōrmis (neuter pirifōrme); third-declension two-termination adjective (New Latin)

1. pear-shaped, pyriform

Inflection

Third-declension two-termination adjective.

Number	Singular			Plural
Case / Gender	Masc./Fem.	Neuter		Masc./Fem.	Neuter
Nominative	pirifōrmis	pirifōrme		pirifōrmēs	pirifōrmia
Genitive	pirifōrmis			pirifōrmium
Dative	pirifōrmī			pirifōrmibus
Accusative	pirifōrmem	pirifōrme		pirifōrmēs pirifōrmīs	pirifōrmia
Ablative	pirifōrmī			pirifōrmibus
Vocative	pirifōrmis	pirifōrme		pirifōrmēs	pirifōrmia

Descendants

• → English: pyriform, piriform; piriformis, pyriformis
• → Spanish: piriforme