体质
tǐzhí · HSK 7
constitution
💪 体 (body) + 质 (quality/nature) = your body's quality, i.e. physical constitution
体 is body and 质 is substance or innate quality, so 体质 is the body's built-in quality: your physical constitution or makeup. The pun helper: tǐzhí sounds a bit like teddy-zhi, a teddy bear's sturdy build.