Although ore2 (the adverb) and ure1 (the substantive) ultimately share the same Latin root hora, they are traditionally treated as separate entries in dictionaries. The distinction is occasionally problematic, particularly in some locutions.
The locution (a) dreit ure is prone (probably already in medieval times) to confusion with a dreiture. However, the different etymologies of ure1 (from Latin hora) and dreiture (the adjective dreit followed by the suffix -ure) require separate treatment. To add to the confusion, see also the locution dreit ore sub ore2. Similarly, the locution a mal ure has considerable overlap with a malure (see sub eur1).