arguably
adv.used when you want to say that something is probably true, even if not everyone agrees. It helps you make a strong claim while showing it is your opinion.
adv.used to qualify a statement by indicating that, while perhaps not universally accepted, a strong case can be made for its validity.
“This is arguably the best pizza in the city.”
“The new law is arguably the most significant piece of social legislation passed in the last decade.”
“While critics remain divided on the director's later works, his debut film is arguably the most influential piece of cinema to emerge from that specific artistic movement.”
Sentence adverb — typically placed before an adjective or at the beginning of a clause to modify the entire statement.
Learners often treat 'arguably' like 'arguable' or 'likely'; it should modify a specific claim or adjective rather than acting as a dummy subject complement.
Usage arguably the best
“Halliday thinks the squad "shouldn't be that imbalanced this late into the transfer window" and reckons they need "three centre-halves, one left-back, two, arguably, three wingers".”
“This is arguably the important part of Maresca's system at City so far.”
Common in culture writing
From arguable + -ly.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.