A biological response where an organism develops increased sensitivity or reaction to a substance after previous exposure to a different but related substance.
From Greek 'epi-' (upon, besides) + 'phylaxis' (protection, guarding, from 'phylassein' to guard). A medical term combining the protective concept with sequential exposure.
This is nature's confusing alarm system—your immune system sees something new and thinks 'this looks like trouble!' based on something vaguely similar it encountered before, causing an exaggerated response.
Complete word intelligence in one call. Free tier — 50 lookups/day.