An advance, especially at another's expense; an encroachment. Often used in the plural: Foreign products have made inroads into the American economy. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "inroad" in a sentence
"Like the cyberpunks, these writers give us an 'inroad' for understanding and adapting to rapid change in technology."
"They're visual trickery in fash form, a 12 quid inroad to cool."
"As a result, a cap of £10,000 would make a massive inroad into the finances of the main parties."