1. just a second - Noun
2. just a second - Interjection
(literally) Only one second; a passage of time one-sixtieth of a minute in duration.
(idiomatic) A short period of time, typically anywhere from a few seconds to several minutes or more.
just a second
(idiomatic) Stop; wait. Used to indicate that the speaker wishes the previous speaker or the proceedings to stop so that he or she can comment on what has been said or has happened so far.
We'll be back to our nature documentary, 'Baggy the Anorexic Elephant' in just a second. Colin Mochrie
[to camera] Excuse me for just a second. [walks off-camera, to studio audience] Shut up! Craig Ferguson
I always find it kind of embarrassing, kind of funny, and kind of exciting. In New York I'm recognized a lot, although nobody says anything. You know, they stare at you just a second too long. But in Paris it's not as commonplace to be recognized. Marc Jacobs
I travel without barely any luggage. Just a second set of underwear and binoculars and a map and a toothbrush. Werner Herzog
A racehorse that consistently runs just a second faster than another horse is worth millions of dollars more. Be willing to give that extra effort that separates the winner from the one in second place. H. Jackson Brown, Jr.