1. On, upon: This is the most common meaning, similar to modern English. It indicates a position of something on top of something else.
* "He stōd on þære eorðan." (He stood on the earth.)
* "Sēo sunne scīneð on þā dæg." (The sun shines on the day.)
2. In, at, to: "On" can also indicate location, similar to "in" or "at" in modern English.
* "He wæs on his hūse." (He was in his house.)
* "He cōm on þā ceastre." (He came to the city.)
3. Concerning, about: "On" can also indicate the subject of something, similar to "about" in modern English.
* "He spræc on þā þing." (He spoke about those things.)
* "He wrat on þā sōðnesse." (He wrote about the truth.)
4. Against, towards: "On" can also express movement or action directed towards something.
* "He fōr on þā burg." (He went towards the city.)
* "He fēoll on þā grund." (He fell to the ground.)
5. With, by: In some cases, "on" can indicate a means or accompaniment.
* "He slōh his feond on his sweord." (He slew his enemy with his sword.)
* "He fōr on his hors." (He rode on his horse.)
It's important to consider the surrounding words and the overall context of the sentence to determine the precise meaning of "on" in Old English.