'pseudo-agglutinin' originates from Greek, specifically the prefix 'pseudo-' meaning 'false' and the root 'agglutinin' from Latin 'agglutinare,' meaning 'to glue together.'

'agglutinare' transformed into the English word 'agglutinin,' and the prefix 'pseudo-' was added to form 'pseudo-agglutinin.'

Initially, it meant 'a false or non-standard agglutinin,' and this meaning has largely remained the same in modern usage.