Complex sentence: Hypoallergenic is the characteristic of provoking fewer allergic reactions in allergy sufferers, to have a "decreased" tendency to cause allergies; "hypo" means "less", not "none".
Split into simpler sentences: Hypoallergenic is the characteristic of provoking fewer allergic reactions in allergy sufferers. Hypoallergenic means to have a "decreased" tendency to cause allergies; "hypo" means "less", not "none".