IPA: /fəˈræmɪnəs/
KK: /fɔˈræmɪnəs/
Having many small holes or openings.
The foraminous structure of the sponge allows water to flow through it easily.
Foraminous is formed from "foramen" (from Latin, meaning opening or hole) and the suffix "-ous" (meaning full of). The word describes something that is full of openings or holes.
Think of 'foramen' meaning an 'opening' — that's why foraminous refers to something that is full of openings.