arachnoid

• IPA^(key): /əˈɹæk.nɔɪd/
• Rhymes: -æknɔɪd

Mid 18th century borrowing from New Latin arachnoīdēs, from Ancient Greek ᾰ̓ρᾰχνοειδής (arakhnoeidḗs, “like a cobweb”), from ᾰ̓ρᾰ́χνη (arákhnē, “spider web”) +‎ -ο- (-o-) +‎ -ειδής (-eidḗs, “-oid, -like”). By surface analysis, arachn- +‎ -oid.

arachnoid (not comparable)

1. Relating to or resembling spider webs; covered with or composed of soft loose hairs or fibers.
2. (anatomy) Relating to the arachnoid mater.

• arachnoid mater
• periarachnoid
• subarachnoid
• superarachnoid

arachnoid (plural arachnoids)

1. (neuroanatomy) Ellipsis of arachnoid mater..
2. (astronomy) A round network of fractures in the crust of Venus.

• arachnoidal
• arachnoidian
• arachnoiditis

19th century from translingual Arachnida +‎ -oid.

arachnoid (not comparable)

1. (arachnology, relational) Relating to or resembling spiders.

arachnoid (plural arachnoids)

1. An arachnid.

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