Rhu has 3 different meanings across 1 category:
Proper Noun
Noun
1
Initialism of radioisotope heater unit. (a device that generates heat from the natural decay of radioactive material)
Proper Noun
1
Initialism of Random House Dictionary of the English Language Unabridged.
2
A village west of Helensburgh in Argyll and Bute council area, Scotland (OS grid ref NS2684).