Second (disambiguation)

Second may refer to:

* 2 (number), as an ordinal (also written as "2d" or "2nd")
* Second, a unit of time
* Arcsecond, a unit of angle
* Second of right ascension, in astronomy
* Second (parliamentary procedure), to support a proposal
* Second, the agent of a participant in a duel
* Second, the climber who follows the lead climber in rock climbing
* Second, an assistant to a chess player, in areas such as opening preparation and adjournment analysis
* Second-class degree or second-class honours, a British undergraduate degree classification
* Seconds, substandard or second-hand goods
* "Seconds", a 1966 film directed by John Frankenheimer and starring Rock Hudson
* "Seconds", a song by U2 from their 1983 album, "War"
* "Seconds", an album by Grand Central Records artist Kate Rogers
* Second-in-command, a deputy commander in British and Commonwealth armies
* "Seconds (The Batman)", a fourth-season episode of "The Batman"

In music:

* Minor second, or semitone
* Neutral second, or three-quarters-tone (i.e., one-and-a-half semitones)
* Major second, or whole tone (i.e, two semitones)
* Augmented second, or either one-and-one-quarter tones (i.e., two-and-a-half semitones) or one-and-one-half tones (i.e., three semitones)