Synonyms of permeable

2 Syllables
pervious, porous, gritty, grittier, spongy
3 Syllables
transparent, porose, absorbent, calculous, pulverant, hyaline, bibulous, passable
4 Syllables
accessible, enterable, retentive, absorptive, spongelike, cellophane
6 Syllables
assimilative, assimilatory