infill

noun

in·​fill ˈin-ˌfil 

1

: material that fills in something (such as a hole or the spaces between a building's structural members)

volcanic infill

fiberglass infill

The artificial turf being used contains infill that is made from recycled tires …

—Greg Fitzpatrick

It's framed with hand-hewn cypress posts and beams, though instead of … brick infill … the walls are formed from … a mixture of mud, moss, and animal hair that was once used by native Americans living in the area.

—Amy R. Hughes

2

: new buildings constructed in the space available between existing structures

Urban infill, a big theme these days in city planning, is essentially the opposite of "urban sprawl." As cities grow, planners are looking for ways to pack more people into places that are already developed.

—Franklyn Cater

—often used before another noun

St. Louis must be the infill capital of the nation. Liberally scattered over the city, especially in the older parts, you see clumps and blocks of new apartments, condominia and row houses tucked in among centenarian neighbors.

—E. F. Porter

infill housing

infill verb, transitive + intransitive

infilled; infilling

… it was easier to achieve the vaults themselves by building them of a framework of ribs infilled with webs.

—James F. O'Gorman

Stump holes can be expected to infill with material from the pit walls and immediate vicinity …

—Jonathan D. Phillips et al.

Examples of infill in a Sentence

Recent Examples on the Web

Slipped into the lot, the 1,200-square-foot ADU, or IDU as the architects like to refer to the infill dwelling unit, was built an inch from the 1920s bungalow, five feet from the duplex and four feet from the property line. —Lisa Boone, Los Angeles Times, 21 Nov. 2023

The 2003 blaze’s lessons accelerated a shift toward urban infill development and away from building in fire-prone backcountry areas. Oct. 22, 2023 Restoring Cuyamaca’s tree canopy is years away. —San Diego Union-Tribune, 23 Oct. 2023

The Morena District and Clairemont should be prime candidates for infill projects dedicated to students. —Phillip Molnar, San Diego Union-Tribune, 15 Sep. 2023

Based on numerous comments from neighbors opposed to the Noble Station apartment complex in recent weeks, area residents would rather stick with infill, mixed-income or even market-rate housing as another approach to build capacity. —Thomas Jewell, cleveland, 19 Sep. 2023

The city held a couple of community meetings last fall to hear residents’ concerns, and switched from crumb rubber infill to thermoplastic elastomers (TPE) infill for the new turf to reduce PFAS leakage. —Sarah Raza, BostonGlobe.com, 3 Aug. 2023

Many of the Angelenos converting garages into guest houses — particularly higher income people — aren’t renting them out, and are instead using them as guest rooms or pool houses, said Mott Smith, principal with Civic Enterprise Development, an urban infill developer. —Noah Bierman, Los Angeles Times, 23 Aug. 2023

While development may become a key issue in this race, this isn’t to say Goldbeck wouldn’t support expanding infill development or that Montgomery Steppe would be opposed to new subdivisions. —Michael Smolens, San Diego Union-Tribune, 14 July 2023

This includes brooming out the rubber infill in the turf, watering down and sanitizing that infill and making sure the field is clear of garbage and debris. —Lucas Gordon, The Arizona Republic, 13 Oct. 2022

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Word History

First Known Use

1939, in the meaning defined at sense 1