Final answer:
The combining vowel for 'adenoma' is 'o', used to link the word root to its suffix. The combining form 'adenoid' means resembling a gland.
Step-by-step explanation:
The combining vowel for the term adenoma is 'o'. A combining vowel is commonly used in medical terminology to connect word roots to their suffixes or to another root, even when the second element begins with a vowel. This aids in pronunciation. In adenoma, 'aden' is the root that relates to a gland, and 'oma' is the suffix that indicates a tumor or mass.
The 'o' is the combining vowel making the term easier to pronounce. The combining form 'adenoid' refers to gland-like or glandular. It's derived from the word 'aden' meaning gland and the suffix '-oid' meaning resembling. In medical contexts, 'adenoid' often specifically refers to the adenoid glands, which are lymphoid tissues located in the back of the nasal cavity.