Question

what is defination of a second

Answer 1

The second is the SI base unit of time, commonly understood and historically defined as 1/86,400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each. 

Unit system: SI base unit

Answer 2

1.constituting number two in a sequence; coming after the first in time or order.
2.subordinate or inferior in position, rank, or importance.
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