精せい虫ちゅうせいちゅうMeanings1nounspermatozoon; spermBiological term for a single sperm cell. In everyday contexts, 精子 (せいし) is more common.精せい虫ちゅうは卵らん子しと結けつ合ごうして受じゅ精せいが起おこる。A spermatozoon fuses with an ovum to cause fertilization.