There are some words that appear to be complete homonyms other than by the length of a vowel. For example, there is the word labellum, which can mean either a lip (part of the body) or a basin/sink. In both cases the word is neuter and the two words decline identically. However, the "a" in the word meaning lip is short, but it is long in the case of the basin.
In poetry this difference in vowel sound can be detected by the meter of the verse, but what about prose? In written prose is there any way to detect such a difference?