How do you reply to I second that?
The answer is nothing more than “support” (“I support the motion.”) Note indeed that the definition of “seconder” is, indeed, “the first person to support the motion”. Indeed you need never use the word “second”, just stand and say “I support that”.
Is it I second this or I second that?
The conventional expression is, “I second the motion” or “I second that motion.” In a group that uses Robert’s Rules of Order, a measure can’t be considered unless someone moves it – makes a motion – and another person seconds it – seconds the motion.
What does 2nd mean?
coming next
Definitions of 2nd. adjective. coming next after the first in position in space or time or degree or magnitude. synonyms: 2d, second ordinal.