infidel /inˈfi-del or -dl/

1. Someone who rejects a religion, esp Christianity or Islam
2. Loosely, someone who disbelieves in a particular theory, etc

1. Unbelieving
2. Sceptical
3. Disbelieving a religion

infidelˈity noun

1. Lack of faith or belief
2. Disbelief in religion
3. Unfaithfulness, esp in marriage
4. An instance of this
5. Treachery

• step on it
• step on the gas
• step on the juice
• step out
• step out of line
• step-parent
• step-parenting
• step-parents
• steppe
• stepped
• stepped-index fibre
• stepper
• steppers
• steppes
• stepping
• stepping-stone
• stepping-stones
• step rocket
• step rockets
• steps
• step short
• stepsister
• stepsisters
• step-son
• step stone