prognosticate (v.)

• adumbrate
• announce
• augur
• bet
• betoken
• divine
• dope
• forebode
• forecast
• foresee
• foreshadow
• foretell
• gamble
• guess
• harbinger
• herald
• portend
• predict
• prefigure
• presage
• prophesy
• risk
• signal
• speculate
• vaticinate