Living daylights — idiom for “eyes” (early 1700s). The “eyes” meaning began going out of use in the 1800s, and the phrase “beating the daylights out of someone,” meaning a severe beating, emerged. Now generally used only as an intensifier, such as “to scare the living daylights out of someone.” A poem by Augustus Peirce: The Rebelliad, 1842:
The people used to turn about,
And knock the rulers’ daylights out
Namby-pamby — childish, lacking character, insipid, weak, indecisive, sentimental, effeminate in behavior or expression. It originates from a satirical poem, Namby Pamby (1725), by Henry Carey, lambasting Ambrose Philips, who wrote dreadful sentimental and sycophantic poems that eulogised the children of aristocratic friends. Carey’s Namby Pamby had so much success that people began to call Philips himself “Namby Pamby.”
Ragamuffin — a child who is dirty and unkempt with tattered or ragged clothing. Synonyms include guttersnipe, hobo, vagabond, and tatterdemalion. Its origin dates back to the late 1300s, when Ragamoffyn was used as the name of a demon in a poem titled Piers Plowman. The Ragamuffin is also a breed of domestic cat. It was once considered to be a variant of the Ragdoll cat but was established as a separate breed in 1994.
Rag, tag, and bobtail — riffraff, an unsavory bunch of folks. “Bobtail” was once slang for “contemptible rascal,” while tag was used to mean “torn cloth.” Samuel Pepys, in his Diary for 6th March 1659, writes, “The dining-room… was full of tag, rag, and bobtail, dancing, singing, and drinking.”
A day late and a dollar short — Too little too late. You missed an opportunity because you slept in and didn’t bring enough cash or didn’t work hard enough. (Late 1800s) (Thanks to Greg and Patti for the suggestion.)