preemergent

or pre-e·mer·gent

[pree-i-mur-juh nt]

adjective Horticulture.

of or relating to seedlings before they emerge or appear above ground: a preemergent weed-killer.

noun

a preemergence chemical, as a herbicide.

Origin of preemergent

First recorded in 1955–60; pre- + emergent
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019