Final answer:
Virginia Woolf uses the figurative language device of meiosis to downplay the importance of 'health', 'money', and 'houses' by calling them 'grossly material things' in her extended metaphor about the spider's web.
Step-by-step explanation:
In Virginia Woolf's extended metaphor about the spider's web, when she mentions that we are 'attached to grossly material things, like health and money and the houses we live in', she is using the figurative language device known as meiosis. Meiosis is a form of understatement that deliberately downplays the importance or size of something, often for ironic effect. By referring to critical aspects of human survival and comfort such as 'health', 'money', and 'houses' as 'grossly material things', Woolf minimizes their perceived importance, perhaps to contrast them with more spiritual or intellectual pursuits.