New American Oxford Dictionary
arguably
ar gu a bly |ˈärgyo͞oəblē ˈɑrɡj (əw )əbli | ▶adverb [ sentence adverb ] it may be argued (used to qualify the statement of an opinion or belief ): she is arguably the greatest woman tennis player of all time.
Oxford Dictionary
arguably
ar ¦gu |ably |ˈɑːɡjuəbli | ▶adverb [ sentence adverb ] it may be argued (used to qualify the statement of an opinion or belief ): she is arguably the greatest woman tennis player of all time.
American Oxford Thesaurus
arguably
arguably adverb this is arguably the best Broadway musical in ten years: possibly, conceivably, feasibly, plausibly, probably, maybe, perhaps.
Oxford Thesaurus
arguably
arguably adverb these criteria are exceedingly vague and arguably provide too much scope for judicial interpretation: possibly, conceivably, feasibly, plausibly, probably, maybe, perhaps, potentially; debatably, contestably, controversially.
Sanseido Wisdom Dictionary
arguably
á r gu a bly 副詞 〖文修飾; しばしば最上級 比較級の前で 〗まず間違いなく, きっと ; たぶん, おそらく (!もったいぶって自分の主張を述べるニュアンスがある; →actually 読解のポイント ) .