keep on
— Verb
– English
~ allow to remain in a place or position or maintain a property or feature; "We cannot continue several servants any longer"; "She retains a lawyer"; "The family's fortune waned and they could not keep their household staff"; "Our grant has run out and we cannot keep you on"; "We kept the work going as long as we could"; "She retained her composure"; "this garment retains its shape even after many washings"
knock-on effect
— Noun
– English
~ a secondary or incidental effect
knock on
— Noun
– English
~ (rugby) knocking the ball forward while trying to catch it (a foul)