Origin and history of second

c. 1300, "next in order, place, time, etc., after the first; an ordinal numeral; being one of two equal parts into which a whole is regarded as divided;" from Old French second, secont, and directly from Latin secundus "following, next in time or order," also "secondary, subordinate, inferior," from PIE *sekw-ondo-, pariticipal form of root *sekw- "to follow."

It replaced native other in this sense because of the ambiguity of the earlier word. From late 14c. as "other, another" (as in "No Second Troy"), also "next in order in rank, quality, or importance."

Second sight is from 1610s; it presumably implies a second way of seeing in addition to the physical sight with the eyes, but it is etymologically perverse as it means the sight of events before, not after, they occur or are revealed. Second-degree in a general sense of "next to lowest on a scale of four" in Arostotelian qualities is from Middle English; in reference to burns, by 1890.

Second fiddle is attested by 1809:

A metaphor borrowed from a musical performer who plays the second or counter to one who plays the first or the "air." [Bartlett, "Dictionary of Americanisms," 1848]

To play first violin, figuratively as "take the leading part" is attested by 1780.

Latin secundus, tertius, etc. appended to personal names in English schools (to designate boys having the same surname by order of seniority) is attested by 1826s.

"one-sixtieth of a minute of degree," also "sixtieth part of a minute of time," late 14c. in geometry and astronomy, seconde, from Old French seconde, from Medieval Latin secunda, short for secunda pars minuta "second diminished part," the result of the second division of the hour by sixty (the first being the "prime minute," now simply the minute), from Latin secunda, fem. of secundus "following, next in time or order" (see second (adj.)).

The second hand of a clock, the pointer indicating the passage of seconds, is attested by 1759.

1580s, "to support or represent (someone)," especially in a duel, pugilistic contest, etc., from French seconder, from Latin secundare "to assist, accommodate, direct favorably" (source also of Spanish segundar), from secundus "assisting, favorable; following, next in time or order" (see second (adj.)). The parliamentary sense is recorded by 1590s: "formally to express approval and support of (a motion, etc.) as a necessary preliminary to further discussion." Related: Seconded; seconding.

early 14c., "the one next in order after another or the first," from second (adj.). Also compare Middle English seconde (n.) "one who is second in authority." As "assistant, supporter," especially "one who attends a principal in a duel or pugilistic contest," by 1580s (from second (v.)). As short for second base in U.S. baseball, by 1861.