Meaning of or in English
Conjunction
1. used to express a choice or difference
I want an orange or an apple.
2. used to warn or advise someone that something bad could happen if they does not do a particular thing; and if not
Get up, or you'll be late. ― If you do not get up, you'll be late. ― Get up, otherwise you'll be late.
3. used to introduce a word or phrase that gives a more specific information; in other words
1 mile, or about 1.6 kilometers