"turf, slice of earth with grass on it," mid-15c., apparently from Middle Dutch sode "turf," or Middle Low German sode, both related to Old Frisian satha "sod," all of uncertain origin. Perhaps the notion is water saturation and the group is related to sog. The (old) sod "Ireland" is from 1812.
c.1400, "to cover with sod," from sod (n.). Related: Sodded; sodding.
in sod off (1960), British slang term of dismissal; see sod (n.2).
Old English seoþan "to boil," also figuratively, "be troubled in mind, brood" (class II strong verb; past tense seaþ, past participle soden), from Proto-Germanic *seuthan (cf. Old Norse sjoða, Old Frisian siatha, Dutch zieden, Old High German siodan, German sieden "to seethe"), from PIE root *seut- "to seethe, boil."
Driven out of its literal meaning by boil (v.); it survives largely in metaphoric extensions. Figurative use, of persons or populations, "to be in a state of inward agitation" is recorded from 1580s (implied in seething). It had wider figurative uses in Old English, e.g. "to try by fire, to afflict with cares." Now conjugated as a weak verb, and past participle sodden (q.v.) is no longer felt as connected.
to boil (Ex. 16:23).