expression
came; went; was/were (somewhere); was/were (doing)
Honorific past form of いる, 行く, or 来る, used to refer respectfully to someone's movement or state. Abbreviation of いらっしゃった, common in casual polite speech.
先生はもういらした？
Has the teacher already arrived?
昨日はどちらにいらしたんですか。
Where were you yesterday? (honorific)