敝 is a literary-style attributive word with two main uses. Literally it means 'shabby, worn-out', describing physical items like clothes. More commonly in formal or written Chinese, it functions as a humble prefix before nouns related to yourself or your own group — like 敝公司 ('our company'), 敝姓 ('my surname') — similar to how 'my' or 'our' is used in polite English correspondence. You'll rarely hear it in casual speech; it belongs to formal letters, introductions, or self-deprecating openings.