rytidiadelfus: both h's gone
heard as rytidiadelfus
spelled rhytidiadelphus
This is the name with every silent letter stripped out. Written properly it is rhytidiadelphus.
What the ear did
The version is a good record of what the word sounds like and a poor record of what it is. Greek gave the name two h's that do no audible work: one in rh at the front, one inside ph near the end.
R-H-Y-T-I-D-I-A-D-E-L-P-H-U-S
The full entry for rhytidiadelphus covers the name itself.