an act that starts something; start; beginning.
Baseball. the player who is first in the batting order or who is first to bat for a team in an inning.
Origin of leadoff
First recorded in 1890–95; noun use of verb phrase lead off
leading off or beginning: the lead-off item on the agenda.
Origin of lead-off
First recorded in 1885–90; adj. use of verb phrase lead off
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019