Overwhelming is a form of Overwhelm. Seize is a type of Overwhelm. Rack is a type of Seize. Spit is part of Rack. 
Regard is etymologically related to Guard. 
Overwhelming --FormOf--> Overwhelm <--IsA-- Seize <--IsA-- Rack <--PartOf-- Spit 
Guard <--EtymologicallyRelatedTo-- Regard 