1.
row of houses; house after house
A line of buildings standing side by side along a street.
2.
across the board; without exception; one after another
Used adverbially to indicate that something applies to every case in a group, without exception. Very common in news and business reporting.
Compound of 軒 (eaves, house) + 並み (row, line). Originally described a row of houses, but the adverbial sense 2 is now more common.
As an adverb, 軒並み emphasizes that something affects every member of a group uniformly. It is especially frequent in news reporting about market trends, price changes, and widespread phenomena.