"resembling a sponge," 1774, from Latin spongia "sponge" (see sponge (n.)) + forma "form, shape" (see form (n.)).
Entries linking to spongiform
sponge n.
Old English sponge, spunge, from Latin spongia "a sponge," also "sea animal from which a sponge comes," from Greek spongia, related to spongos "sponge," of unknown origin. "Probably a loanword from a non-IE language, borrowed independently into Greek, Latin and Armenian in a form *sphong-" [de Vaan]. The Latin word is the source of Old Saxon spunsia, Middle Dutch spongie, Old French esponge, Spanish esponja, Italian spugna.
In English in reference to the marine animal from 1530s. To throw in the sponge "quit, submit" (1860) is from prizefighting, in reference to the sponges used to cleanse the faces of combatants between rounds (compare later throw in the towel). Sponge-cake is attested from 1808.
form n.
c. 1200, forme, fourme, "semblance, image, likeness," from Old French forme, fourme, "physical form, appearance; pleasing looks; shape, image; way, manner" (12c.), from Latin forma "form, contour, figure, shape; appearance, looks; a fine form, beauty; an outline, a model, pattern, design; sort, kind condition," a word of unknown origin. One theory holds that it is from or cognate with Greek morphe "form, beauty, outward appearance" (see Morpheus) via Etruscan [Klein].
From c. 1300 as "physical shape (of something), contour, outline," of a person, "shape of the body;" also "appearance, likeness;" also "the imprint of an object." From c. 1300 as "correct or appropriate way of doing something; established procedure; traditional usage; formal etiquette." Mid-14c. as "instrument for shaping; a mould;" late 14c. as "way in which something is done," also "pattern of a manufactured object." Used widely from late 14c. in theology and Platonic philosophy with senses "archetype of a thing or class; Platonic essence of a thing; the formative principle." From c. 1300 in law, "a legal agreement; terms of agreement," later "a legal document" (mid-14c.). Meaning "a document with blanks to be filled in" is from 1855. From 1590s as "systematic or orderly arrangement;" from 1610s as "mere ceremony." From 1550s as "a or rank at school" (from sense "a fixed course of study," late 14c.). Form-fitting (adj.) in reference to clothing is from 1893.