noun
armchair; chair with armrests
Standard word for a chair with armrests.
父は肘掛け椅子に座って新聞を読んでいる。
My father is sitting in an armchair reading the newspaper.
noun
senior staff;
Metaphorical use likening a senior employee to a comfortable armchair; somewhat colloquial and not extremely common.
彼は会社の肘掛け椅子で、もう何年も重要な決定に関わっている。
He is a senior staff member at the company and has been involved in important decisions for years.