To agree as a second person to (a proposal), usually to reach a necessary quorum of two. (See under #Etymology 3 for translations.)
I second the motion.
To follow in the next place; to succeed.
To climb after a lead climber.
To transfer temporarily to alternative employment.
The army officer was seconded while he held civil office.
To assist or support; to back.
To agree as a second person to (a proposal), usually to reach a necessary quorum of two. (This may come from the English adjective above.)
I second the motion.
To accompany by singing as the second performer.