ARACHNOID

Pronunciation (US):

(GB):

 Dictionary entry overview: What does arachnoid mean? 

• ARACHNOID (noun)
  The noun ARACHNOID has 2 senses:

1. the middle of the 3 meninges

2. air-breathing arthropods characterized by simple eyes and four pairs of legs

  Familiarity information: ARACHNOID used as a noun is rare.

• ARACHNOID (adjective)
  The adjective ARACHNOID has 1 sense:

1. relating to or resembling a member of the class Arachnida

  Familiarity information: ARACHNOID used as an adjective is very rare.

 Dictionary entry details 

• ARACHNOID (noun)

Sense 1

Meaning:

The middle of the 3 meninges

Classified under:

Nouns denoting body parts

Synonyms:

arachnoid; arachnoid membrane

Hypernyms ("arachnoid" is a kind of...):

meninges; meninx (a membrane (one of 3) that envelops the brain and spinal cord)

Holonyms ("arachnoid" is a part of...):

leptomeninges (the two innermost layers of the meninges; cerebrospinal fluid circulates between these innermost layers)

Sense 2

Meaning:

Air-breathing arthropods characterized by simple eyes and four pairs of legs

Classified under:

Nouns denoting animals

Synonyms:

arachnid; arachnoid

Hypernyms ("arachnoid" is a kind of...):

arthropod (invertebrate having jointed limbs and a segmented body with an exoskeleton made of chitin)

Hyponyms (each of the following is a kind of "arachnoid"):

daddy longlegs; harvestman; Phalangium opilio (spiderlike arachnid with a small rounded body and very long thin legs)

scorpion (arachnid of warm dry regions having a long segmented tail ending in a venomous stinger)

false scorpion; pseudoscorpion (small nonvenomous arachnid resembling a tailless scorpion)

whip-scorpion; whip scorpion (nonvenomous arachnid that resembles a scorpion and that has a long thin tail without a stinger)

spider (predatory arachnid with eight legs, two poison fangs, two feelers, and usually two silk-spinning organs at the back end of the body; they spin silk to make cocoons for eggs or traps for prey)

acarine (mite or tick)

Holonyms ("arachnoid" is a member of...):

Arachnida; class Arachnida (a large class of arthropods including spiders and ticks and scorpions and daddy longlegs; have four pairs of walking legs and no wings)

Derivation:

arachnoid (relating to or resembling a member of the class Arachnida)

• ARACHNOID (adjective)

Sense 1

Meaning:

Relating to or resembling a member of the class Arachnida

Classified under:

Relational adjectives (pertainyms)

Synonyms:

arachnidian; arachnoid; spiderlike; spiderly; spidery

Domain category:

zoological science; zoology (the branch of biology that studies animals)

Pertainym:

class Arachnida (a large class of arthropods including spiders and ticks and scorpions and daddy longlegs; have four pairs of walking legs and no wings)

Derivation:

arachnoid (air-breathing arthropods characterized by simple eyes and four pairs of legs)

 Context examples 

A disorder characterized by inflammation of the arachnoid membrane and adjacent subarachnoid space.

(Arachnoiditis, NCI Thesaurus/CTCAE)

The cavity situated in front of the pons between the temporal lobes over the diencephalon base and where the arachnoid membrane crosses.

(Crural Cistern, NCI Thesaurus)

The two innermost layers of tissue that cover the brain and spinal cord, the arachnoid mater and the pia mater.

(Leptomeninges, NCI Thesaurus)

X-ray visualization of the spinal cord following injection of contrast medium into the spinal arachnoid space.

(Myelography, NLM, Medical Subject Headings)

Inflammation of the arachnoid membrane and adjacent subarachnoid space.

(Arachnoiditis, NCI Thesaurus)

Small projection of the arachnoid membrane through the dura into a venous sinus.

(Arachnoid Villus, NCI Thesaurus)

Intracranial arachnoid cysts may present with headaches, seizures and hydrocephalus.

(Arachnoid Cyst, NCI Thesaurus)

Intracranial arachnoid cysts usually occur adjacent to arachnoidal cistern and may present with HYDROCEPHALUS; HEADACHE; SEIZURES; and focal neurologic signs.

(Arachnoid Cyst, NLM, Medical Subject Headings)

Spinal arachnoid cysts may present with symptoms of radiculopathy.

(Arachnoid Cyst, NCI Thesaurus)

Spinal arachnoid cysts may be extradural, intradural, or perineural and tend to present with signs and symptoms indicative of a RADICULOPATHY.

(Arachnoid Cyst, NLM, Medical Subject Headings)