"Ere" is an old-fashioned and poetic word that means "before" or "preceding in time". It is not commonly used in modern English, but can still be found in literature and poetry. The word can be used as a preposition, conjunction, or adverb. For example, "I shall be back ere nightfall" means "I will be back before nightfall". In some cases, "ere" can also be used as a slang interjection in the UK to emphasize an opinion or want.