shimmer (n.) Look up shimmer at Dictionary.com
"a tremulous light," 1821, from shimmer (v.).
shimmer (v.) Look up shimmer at Dictionary.com
Old English scimerian "to glitter, shimmer, glisten, shine," related to (perhaps a frequentative of) scimian "to shine," from Proto-Germanic *skim- (cognates: Swedish skimra, Dutch schemeren "to glitter," German schimmern), from PIE root *skai- "to gleam, to shine" (see shine (v.). Related: Shimmered; shimmering.