"a small particular or detail, a trivial fact," 1751, usually in plural minutiae, from Latin minutia "smallness" (plural minutiae, in Late Latin "trifles"), from minutus "small" (from PIE root *mei- (2) "small").
"top of the head," early 14c. (late 12c. in surnames), of unknown origin; perhaps a shortened form of Old French patene or Medieval Latin patena, both from Latin patina "pan, dish" (see pan (n.)). "[U]sually employed in a trivial or derogatory sense" [Century Dictionary].
also bull shit, "eloquent and insincere rhetoric," 1914, American English slang; see bull (n.1) + shit (n.), probably because it smells. But bull in the sense of "trivial or false statements" (1914), which usually is associated with this, might be a continuation of Middle English bull "false talk, fraud" (see bull (n.3)).
trivial term of endearment, by 1910, from the name of the baby added in 1907 to the popular "New York World" comic strip "The Newlyweds" by U.S. cartoonist George McManus. The name is perhaps from Snooks, proper name used in Britain for "a hypothetical person" (1860; compare Joe Blow in U.S.). As an actual proper name, Snooks dates back to the Domesday Book and may be from Old English *snoc "a projecting point of land" (perhaps here with sense of "a big nose").
early 15c., "hairy, shaggy, bristling," from Latin horridus "bristly, prickly, rough, horrid, frightful, rude, savage, unpolished," from horrere "to bristle with fear, shudder" (see horror). Meaning "horrible, causing horror" is from c. 1600. Sense weakened 17c. to "unpleasant, offensive."
[W]hile both [horrible and horrid] are much used in the trivial sense of disagreeable, horrible is still quite common in the graver sense inspiring horror, which horrid tends to lose .... [Fowler]
word-forming element meaning "small in size or extent, microscopic; magnifying;" in science indicating a unit one millionth of the unit it is prefixed to; from Latinized form of mikros, Attic form of Greek smikros "small, little, petty, trivial, slight," perhaps from PIE *smika, from root *smik- "small" (source also of Old High German smahi "littleness"), but Beekes thinks it a Pre-Greek word.