How many letters does the top answer for “the upper part of the abdomen.” have?

The most common answer is epigastrium (11 letters).

Crossword clue: the upper part of the abdomen.

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

epigastrium 11 letters web-def

the region lying on or over the stomach (just below the sternum)

the lower part of the abdomen. 50% similar → hypogastrium

the upper part of anything 50% similar → top

the upper part of the breastbone 50% similar → manubrium