To betray or go back on.
To cross twice in hybridization, as (A × B) × (C × D); for example, in commercial hybrid seed corn, A through D are classically inbreds, and their grandoffspring is the seed for sale.
To inform on, especially in betrayal of others.
To contact or cooperate with the police for any reason.
A ball used in the sport of Quidditch.
A thief.
An informer, one who betrays his group.
A nose.
A tiny morsel.