frenulum

• fraenulum, frænulum (hypercorrect, nonstandard)

Borrowed from New Latin frēnulum, diminutive of frēnum (“a bridle, curb, bit”).

• (Received Pronunciation) IPA^(key): /ˈfriː.njʊl.əm/
• (General American) IPA^(key): /ˈfrɛn.jəl.əm/

frenulum (plural frenula or frenulums)

1. (anatomy) A small fold or ridge of tissue that supports or restrains the motion of the part to which it is attached, in particular a fold of skin beneath the tongue, or between the lip and the gum.

   Synonym: frenum

   Humans have three oral frenulums: beneath the tongue, between the upper lip and gum, and between the lower lip and gum.

2. (entomology, zootomy) A bristle or row of bristles on the edge of the hindwings of some lepidoptera which unites the wings by interlocking with a catch on the posterior part of the forewings.

• frenular
• frenulate

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

• fraenulum

From frēnum (“a bridle, curb, bit”) +‎ -ulum (diminutive nominal suffix).

• (modern Italianate Ecclesiastical) IPA^(key): /ˈfre.nu.lum/, [ˈfrɛːnulum]

frēnulum n (genitive frēnulī); second declension (New Latin)

1. Diminutive of frēnum.

Second-declension noun (neuter).

• → English: frenulum