[in-fil] 
| 1. | to fill in: The old stream beds have been infilled with sediment. |
| 2. | 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. |
| 3. | of, pertaining to, or involving the use of infill in urban planning: infill condominium projects; infill office buildings and retail space. |
