clan (n.)

“a family, a tribe,” especially, among the Highlanders of Scotland, a form of social organization consisting of a tribe holding land in common under leadership of a chieftain, early 15c., from Gaelic clann “family, stock, offspring,” akin to Old Irish cland “offspring, tribe,” both from Latin planta “offshoot” (see plant (n.)).

The Goidelic branch of Celtic (including Gaelic) had no initial p-, so it substituted k- or c- for Latin p-. The same Latin word in (non-Goidelic) Middle Welsh became plant “children.”

welfare (n.)

c. 1300, from Old English wel faran “condition of being or doing well,” from wel (see well (adv.)) + faran “get along” (see fare (v.)). Similar formation in Old Norse velferð. Meaning “social concern for the well-being of children, the unemployed, etc.” is first attested 1904; meaning “organized effort to provide for maintenance of members of a group” is from 1918. Welfare state is recorded from 1941.

leviathan (n.)

late 14c., “sea monster, sea serpent,” sometimes regarded as a form of Satan, from Late Latin leviathan, from Hebrew livyathan “dragon, serpent, huge sea animal,” of unknown origin, perhaps from root l-w-h- “to wind, turn, twist,” on the notion of a serpent’s coils. If so, related to Hebrew liwyah “wreath,” Arabic lawa “to bend, twist.” Of powerful persons or things from c. 1600. Hobbes’s use is from 1651.

An aquatic animal mentioned in the Old Testament. It is described in Job xli. apparently as a crocodile; in Isa. xxvii 1 it is called a piercing and a crooked serpent; and it is mentioned indefinitely in Ps. lxxiv. 14 as food and Ps. civ. 26. [Century Dictionary]

heritage (n.)

c. 1200, “that which may be inherited,” from Old French iritageeritageheritage “heir; inheritance, ancestral estate, heirloom,” from heriter “inherit,” from Late Latin hereditare, ultimately from Latin heres (genitive heredis) “heir” (see heredity). Meaning “condition or state transmitted from ancestors” is from 1620s.

ambassador (n.)

late 14c., also embassador, “diplomatic emissary of a ruler in the court of another,” from Old French embassatorambassateor, which comes via Provençal or Old Spanish from Latin ambactus “a servant, vassal,” from Celtic amb(i)actos “a messenger, servant,” from PIE root *ambhi- “around” + *ag- “to drive, draw out or forth, move.”

Compare embassy. Forms in am- and em- were used indiscriminately in English 17c.-18c. Until 1893 the United States sent and received none, having only ministers (often called ambassadors), who represented the state, not the sovereign.

perjury (n.)

late 14c., “act of swearing to a statement known to be false,” via Anglo-French perjurie (late 13c.) and Old French parjurée “perjury, false witness,” both from Latin periurium “a false oath,” from periurare “swear falsely,” from per “away, entirely” (see per) + iurare “to swear” (see jury (n.)). Related: Perjurious.

perjury (n.)

late 14c., “act of swearing to a statement known to be false,” via Anglo-French perjurie (late 13c.) and Old French parjurée “perjury, false witness,” both from Latin periurium “a false oath,” from periurare “swear falsely,” from per “away, entirely” (see per) + iurare “to swear” (see jury (n.)). Related: Perjurious.

frivolous (adj.)

mid-15c., from Latin frivolus “silly, empty, trifling, worthless,” diminutive of *frivos “broken, crumbled,” from friare “break, rub away, crumble” (see friable). In law (by 1736), “so clearly insufficient as to need no argument to show its weakness.” Related: Frivolouslyfrivolousness.