KEY: Indomitable.
SYN: Invincible, untamable, irrepressible, indefatigable.
ANT: Effortless, feeble, languid.

• Formation
• Former
• Formidable
• Formless, [See FORM]
• Forsake, [See ABANDON]
• Forswear, [See ABJURE]
• Forthwith
• Fortify
• Fortitude
• Fortuitous
• Fortunate
• Fortune, [See CHANCE]
• Forward
• Foster, [See CHERISH]
• Foul, [See CORRUPT]
• Found
• Foundation
• Founder
• Founder \v
• [Fr
• Fractious
• Fragile
• Fragment
• Fragrant
• Frail