subarachnoid /ˌsʌb.əˈɹæk.nɔɪd/adjective 1noun 1forms 1 adjective1 •Located or occurring below the arachnoid mater, often specifically between the arachnoid membrane and the pia mater.After an internal examination he found that "the cause of death was craniocerebral injury with subarachnoid hemorrhage […]." — 1988 noun1 •Ellipsis of subarachnoid space. formssubarachnoids
