arachnoid
|a-rach-noid|
/əˈræk.nɔɪd/
spider-like; web-like
Etymology
'arachnoid' originates from Greek, specifically the word 'aráchnē' (ἀράχνη), where 'aráchnē' meant 'spider', combined with the suffix '-oid' from Greek 'eidos' meaning 'form' or 'likeness'.
'arachnoid' entered scientific and medical Latin as 'arachnoides' (New Latin) meaning 'spider-like' and was adopted into English in the 18th–19th centuries to describe both spider-like forms and the web-like membrane (arachnoid mater).
Initially, it meant 'spider-like' in a general descriptive sense; over time it acquired a specialized anatomical sense referring to the web-like membrane around the brain and spinal cord, while retaining the broader 'web-like' or 'spider-like' meanings.
Meanings by Part of Speech
Noun 1
the arachnoid (or arachnoid mater): the delicate, web-like middle membrane (meninx) that surrounds the brain and spinal cord.
The surgeon examined the arachnoid for signs of inflammation.
Synonyms
Adjective 1
resembling or characteristic of spiders; spider-like (having features suggestive of a spider or its web).
The sculpture had an arachnoid quality, with thin, interlacing supports like a web.
Synonyms
Last updated: 2025/10/01 05:56