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"shake," c.1400, alteration of chiveren (c.1200), of uncertain origin, perhaps from Old English ceafl "jaw," on notion of chattering teeth. Spelling change of ch- to sh- is probably from influence of shake. Related: Shivered; shivering.
"to break in or into many small pieces," c.1200, from the source of shiver (n.). Chiefly in phrase shiver me timbers (1835), "a mock oath attributed in comic fiction to sailors" [OED]. My timbers! as a nautical oath (probably euphemistic) is attested from 1789 (see timber (n.)). Related: Shivered; shivering.
"small piece, splinter, fragment, chip," c.1200, perhaps from an unrecorded Old English word, related to Middle Low German schever schiver "splinter," Old High German scivero, from Proto-Germanic *skif- "split" (cf. Old High German skivaro "splinter," German Schiefer "splinter, slate"), from PIE *skei- "to cut, split" (see shed (v.)). Commonly in phrases to break to shivers "break into bits" (mid-15c.). Also, shiver is still dialectal for "a splinter" in Norfolk and Lincolnshire.
"a tremulous, quivering motion," 1727, from shiver (v.1). The shivers in reference to fever chills is from 1861.