1. An advance, especially at another's expense; an encroachment: "She had made few inroads in convincing the committee to explore the issue without prejudice" (Mary V. Dearborn).

2. A reduction or diminishment, especially by encroachment: "The inroads on free time made by television and computers have also badly affected the vitality of civil society" (Kenneth Minogue).

3. A hostile invasion; a raid.