When the Famous Five called each other 'fathead', my brother didn't recognise it as a compound word and used to pronounce the first part like the 'fath' in 'father', and the second like the 'ead' in 'bead'.
Nowadays, when I reread (usually Ennis) Dredd calling people 'meathead', I can't help myself pronouncing it in a similar fashion. It sounds ridiculous either way up - did Wagner Dredd ever call someone a meathead (or me-theed)?