'anaphylactoid' originates from English, formed by combining 'anaphylaxis' with the suffix '-oid,' where '-oid' means 'resembling' or 'like.'

'anaphylactoid' was coined in the 20th century in medical English to describe reactions similar to anaphylaxis but not caused by the same immune mechanisms.

Initially, it meant 'resembling anaphylaxis,' and this meaning has remained consistent in medical usage.