As verbs the difference between Tell and mutter
is that
Tell is to count, reckon, or enumerate while
mutter is to utter words, especially complaints or angry expressions, indistinctly or with a low voice and lips partly closed; to say under one's breath.
As nouns the difference between Tell and mutter
is that
Tell is a reflexive, often habitual behavior,
especially one occurring in a context that often features attempts at deception by persons under psychological stress (such as a poker game or police interrogation), that reveals information that the person exhibiting the behavior is attempting to withhold while
mutter is a repressed or obscure utterance; an instance of muttering.