Focus on the pronunciation of infill
English definition of “infill”
// noun [U] PROPERTY
› development of new houses, business buildings, etc. on land between other buildings in already developed areas: The mayor included $2 million in his current city budget to buy land for infill and redevelopment throughout the city. Infill housing is expensive and not everybody who wants a house wants to live downtown. Experts also suggest that the trend toward infill development can reduce the reliance on driving.