How do I solve 7 down in Times Cryptic 29540?

Question

Accepted Answer

7 down reads "Infidel witnessing robbery?" (7 letters); the answer is ATHEIST. It's a charade: the answer breaks into parts in clue order, each part clued by a word or short phrase. No indicators needed; watch for standard abbreviations (RA = artist, US = American, IN = at home) and short synonyms. The full step-by-step breakdown is on this page.

Infidel witnessing robbery? (7)

7D — Infidel witnessing robbery? (7) — ATHEIST