a strong feeling or intuition that something, esp something unpleasant, is going to happen; a presentiment
She felt a premonition of danger
formal a warning of something to come; a forewarning
a premonition of the troubles that lay in store
premonitory /priʹmonit(ə)ri/ adj
[via French from late Latin praemonition-, praemonitio, from Latin praemonēre to warn in advance, from prae- + monēre to warn]