날로 + change verb (날로 심해지다); 날로 먹다 = eat raw / get for free
day by day, increasingly; raw (uncooked)
Example
도시의 교통 문제가 날로 심각해지고 있습니다.
The city's traffic problems are growing more serious by the day.
Word parts
날 'day' + -로. Homonym warning: 날 also means 'raw', so 날로 먹다 = eat raw.
Good to know
Slang 날로 먹다 means 'to get something without any effort'.
Related words