Synonyms for Sure-fire

Synonyms starting with letter I

• infallible

  dependable, certain
• idiot-proof
• inevitable
• impeccable
• inerrant
• insured
• indubitable
• incontestable
• indisputable
• irrefutable
• incontrovertible
• in the bag
• infallibly
• ineluctable
• inescapable
• irrevocable
• irrefragable
• imaginable
• inerrable