I was in a committee meeting over the weekend at which — amongst many other topics — we were discussing how much we ought to pay a visiting speaker. What sort of honorarium should we offer? I noticed with interest and surprise that the person who introduced this topic pronounced the word as ˌhɒnəˈreəriəm, with an initial h-sound.
I’ve always myself said this word as ˌɒnəˈreəriəm , without h, just like its congeners hono(u)r, hono(u)rable, honorary, honest etc, and I assumed that that was what everyone said.
But a quick straw poll when we were having coffee afterwards showed that four out of the ten people present said they preferred the pronunciation with h. This variant is not recorded in any dictionary that I know of.
I suppose we can relate it to the fact that h is silent in heir and heiress but not in the etymologically linked inherit, heredity and heritage. Perhaps some speakers do not ‘feel’ the etymological link between honorarium and the other hono(u)r(-) words, so that there is less pressure to treat them all identically.
Added to that there is the understandable tendency to use a spelling pronunciation for any word that may be relatively unfamiliar, or first encountered in writing rather than in speech.