ðɪs ɪz bɪkˈʌz pˈiːpəl hˌuː kˈɔːld ðɛɹ ɛɡzˈɪstəns "kˈæɾɐkˌoʊm" kəmpˈɛɹd ɪt wɪððə lˈaɪf ʌv ˈɜːli kɹˈɪstʃənz, hˌuː ɐlˈɛdʒᵻdli sˈiːkɹᵻtli ɡˈæðɚd dˈʊɹɹɪŋ ðə pˌɜːsɪkjˈuːʃən tə hˈoʊld ɹᵻlˈɪdʒəs sˈɛɹᵻməniz ɪnðə kˈæɾɐkˌoʊmz ʌv ɹˈoʊm.
This is because people who called their existence "catacomb" compared it with the life of early Christians, who allegedly secretly gathered during the persecution to hold religious ceremonies in the catacombs of Rome.