(CNN) Robert Mueller's investigation of US President Donald Trump; Brett Kavanaugh's tense hearings in Congress; the fight for social, racial and gender equality: the past year has seen an absorbing and tumultuous news cycle.

And now, "justice" -- the crux of some of the most gripping stories of the past 12 months -- has been recognized for its central place in the public consciousness.

US publishing company Merriam-Webster has named the noun its Word of the Year for 2018, after it saw a 74% spike in look-ups compared with 2017.

"The concept of justice was at the center of many of our national debates in the past year: racial justice, social justice, criminal justice, economic justice," the company said when explaining its choice.

"In any conversation about these topics, the question of just what exactly we mean when we use the term justice is relevant, and part of the discussion," it said.