1.
damn!, crap!, shit!
An expletive expressing frustration, anger, or disappointment.
2.
damn, freaking (intensifying prefix)
Used as a prefix before nouns or adjectives to add strong negative emphasis, similar to English 'damn' or 'freaking.'
Register
くそ is vulgar language. While widely used in casual speech, it should be avoided in polite or formal contexts.
As a prefix (sense 2), くそ intensifies the following word negatively:
Usage
The literal meaning is "excrement," but as an expletive and prefix, it functions like English "damn" or "freaking." The kanji form is 糞.
Related Words
Compare:
糞 (dung)