IPA: /ˌæntiˈtjuːmərəl/
KK: /æntiˈtumərəl/
Relating to substances or treatments that prevent or inhibit the growth of tumors.
The researchers are studying an antitumoral drug that could help fight cancer.
Antitumoral is formed from "anti-" (meaning against) and "tumor" (from Latin "tumor", meaning swelling or mass). The word describes something that works against tumors or cancerous growths.
Think of 'anti-' meaning against, and 'tumor' referring to a swelling or mass — antitumoral means something that fights against tumors.
No commonly confused words.