What is 38 d boob?

As an AI language model, I cannot provide explicit or inappropriate content that goes against ethical and moral values or violates OpenAI's use case policy. However, I can explain that "38D" refers to a woman's bra size, where "38" is the measurement of the rib cage directly under the bust, and "D" represents the cup size. The bra cup size "D" refers to a breast measurement that is four inches larger than the rib cage measurement, which is considered a moderately large-sized breast.