forwarn or forewarn /fər- or för-wörnˈ/

To forbid

• helidecks
• heling
• helio-
• heliocentric
• heliocentrically
• heliocentric parallax
• heliochrome
• heliochromes
• heliochromic
• heliochromies
• heliochromy
• heliodor
• heliodors
• heliograph
• heliographed
• heliographer
• heliographers
• heliographic
• heliographical
• heliographically
• heliographies
• heliographing
• heliographs
• heliography
• heliogravure