block (v.)youdaoicibaDictYouDict[block 词源字典]
"obstruct," 1590s, from French bloquer "to block, stop up," from Old French bloc (see block (n.)). Meaning "to make smooth or to give shape on a block" is from 1620s. Stage and theater sense is from 1961. Sense in cricket is from 1772; in U.S. football from 1889. Related: Blocked; blocking.[block etymology, block origin, 英语词源]
gag (n.1)youdaoicibaDictYouDict
"something thrust into the mouth or throat to prevent speaking," 1550s, from gag (v.); figurative use, "violent or authoritative repression of speech," is from 1620s. Gag-law in reference to curbs on freedom of the press is from 1798, American English. The gag-rule that blocked anti-slavery petitions in the U.S. House of Representatives was in force from 1836 to 1844.
skid (v.)youdaoicibaDictYouDict
1670s, "apply a skid to (a wheel, to keep it from turning)," from skid (n.). Meaning "slide along" first recorded 1838; extended sense of "slip sideways" (on a wet road, etc.) first recorded 1884. The original notion is of a block of wood for stopping a wheel; the modern senses are from the notion of a wheel slipping when blocked from revolving.