Synonyms for Unspoken (same or very similar meaning)
WordNet sense 1 (not made explicit):
unexpressed, unsaid, unstated, unvoiced, unuttered, unverbalised, unverbalized
WordNet sense 2 (implied though not directly expressed; inherent in the nature of something):
implicit, inexplicit
WordNet sense 3 (expressed without speech; especially because words would be inappropriate or inadequate):
mute, tongueless, wordless
WordNet sense 4 (without or deprived of the use of speech or words):
inarticulate, unarticulate
From the ODE community, based on WordNet
add/edit