the point or degree to which something extends
"the extent of the damage"
"the full extent of the law"
"to a certain extent she was right"
the distance or area or volume over which something extends
"the vast extent of the desert"
"an orchard of considerable extent"
A range of values or locations.
"The survey mapped every extent of the forest to ensure no patches were left unaccounted for."
In plain English: Extent means how big, wide, or far something reaches.
"The extent of the damage became clear after the storm passed."
Usage: Use extent to describe how far something reaches in size, degree, or scope, rather than referring to a physical location. It answers questions like how large an effect is or how wide a problem spreads.
Extended.
"The fire had spread to an extent that threatened the entire forest."
In plain English: When something is done to an extreme degree, it means it has gone as far as possible.
"The extent damage caused by the storm was far greater than anyone expected."
Usage: Do not use "extent" as an adjective; it is strictly a noun that refers to the degree or scope of something. Instead, use adjectives like "extended," "extensive," or "far-reaching" to describe things that are spread out or large in range.
The word "extent" comes from the Middle English term for a valuation or stretch of land. It traveled into modern usage through Anglo-Norman and Old French roots meaning to spread out or measure an area.