spotted refers the the dried fruits (that resemble spots). dick maybe a corruptions/contraction of the last syllable of pudding, a corruption of dough, or from German dick (“thick, viscous”).
spotted dick (plural spotted dicks)
- A steamed suet pudding containing dried fruit, usually currants; traditional in England.
steamed suet pudding
- Mandarin: 葡萄乾布丁, 葡萄干布丁 (pútáogān bùdīng)
- Finnish: spotted dick (there's nothing similar in Finnish cuisine)