The word "够呛" is formed through a metaphorical extension from a literal physiological reaction to an abstract intensifier, combining the character "够" (gòu), meaning "enough" or "sufficiently," with "呛" (qiàng), which describes the act of choking or being irritated by a strong stimulus (like smoke or spice). Literally, it evokes the image of something being "enough to make one choke." Over time, this concrete sensation was semantically generalized to express that a situation or state is extremely difficult, unbearable, or highly likely to be negative, as in "他病得够呛" (He is terribly ill) or "这事够呛能成" (It's very unlikely this will succeed). Thus, its formation exemplifies how Chinese compounds often create vivid idiomatic meanings by blending tangible experiences with figurative evaluation.