1. Deficient in originality or creativity; lacking powers of invention
   - sterile, unimaginative, uninspired

See also: uncreative

• unfetter
• unfettered
• unfilial
• unfilled
• unfilmed
• unfinished
• unfinished business
• unfirm
• unfit
• unfitness
• unfitting
• unfix
• unfixed
• unflagging
• unflaggingly
• unflappability
• unflappable
• unflattering
• unflavored
• unflavoured
• unflawed
• unfledged
• unflinching
• unflinchingly
• unfluctuating