Any of several large Australian trapdoor spiders of the genus Missulena, especially the dangerous M. occatoria, the male of which has a red head and fangs.
Origin
1930s.
Definition of mouse spider in US English:
mouse spider
noun
Any of several large Australian trapdoor spiders of the genus Missulena, especially the dangerous M. occatoria, the male of which has a red head and fangs.