infill

American  

[in-fil] / ˈɪnˌfɪl /

Or in-fill

verb (used with object)

1. to fill in.

   The old stream beds have been infilled with sediment.

---

noun

1. the planned conversion of empty lots, underused or rundown buildings, and other available space in densely built-up urban and suburban areas for use as sites for commercial buildings and housing, frequently as an alternative to overdevelopment of rural areas.

adjective

1. of, relating to, or involving the use of infill in urban planning.

   infill condominium projects; infill office buildings and retail space.

infill British  

/ ˈɪnfɪlɪŋ, ˈɪnfɪl /

noun

1. the act of filling or closing gaps, etc, in something, such as a row of buildings

2. material used to fill a cavity, gap, hole, etc

3. an acrylic gel application that fills in the gap between a false nail and the root of the real nail, which is created as the real nail grows

---

Etymology

Origin of infill

First recorded in 1875–80; in- ¹ + fill

Example Sentences

City Hall insisted the design followed Football Foundation guidance to contain rubber infill with raised barriers, boot brushes, matting and filtered drainage, which it said Natural England had not objected to.

From BBC • Mar. 6, 2026

Of the roughly 300 stores the company plans to open by 2035, about one-third are expected to be infill locations in existing markets.

From The Wall Street Journal • Feb. 5, 2026

The developers behind the Los Olivos Street project sought to avoid the environmental review, however, because of a new state law that allows many urban infill projects to avoid such requirements.

From Los Angeles Times • Dec. 2, 2025

A few years ago, Kingston was cutting his teeth as an infill developer when he found himself getting outbid for small properties, only to see them transformed into fancy, two-family homes.

From Slate • Apr. 25, 2025

Naught but the clay, as to a rapture fond Could he with fire of genius thus infill!

From The Optimist's Good Morning by Perin, Florence Hobart