E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
When he himself might his quietus make with a bare bodkin. (Hamlet, iii. 1). A stiletto worn by ladies in the hair, not a dagger. In the Seven Champions, Castria took her silver bodkin from her hair, and stabbed to death first her sister and then herself. Praxida stabbed herself in a similar manner. Shakespeare could not mean that a man might kill himself with a naked dagger, but that even a hair-pin would suffice to give a man his quietus.