Allyship is a word about the people standing next to a cause rather than inside it.

Dictionary.com named it Word of the Year for 2021 on 6 December. Its definition is long and precise: the status or role of a person who advocates and actively works for the inclusion of a marginalised or politicised group, not as a member of that group but in solidarity with its struggle and point of view, and under its leadership. The pick was a first for Dictionary.com. It had only added allyship to its dictionary that year, and had never before chosen a word so new to its own pages.

The word itself is not new. Ally goes back to around 1250–1300, ultimately from Latin alligare, "to bind together". Allyship is first attested around 1850, meaning people or nations working together for a common cause. Ally was used in the context of racial justice by the 1940s, and the main modern sense of allyship spread in the 1990s. Dictionary.com's data showed its use rising by an average of over 700% since 2011, with a steep climb in 2020 that carried on into 2021.

Dictionary.com's case was that allyship ran through much of what people talked about in 2021, from workplaces and schools to news and culture. The question it kept raising, Dictionary.com said, was who gets a voice, who deserves empathy, and who and what is valued. It also noted the word was stretching beyond race, gender and sexuality to disability, economic status, and groups such as parents and key workers during the pandemic. Dictionary.com acknowledged that efforts at allyship are often insufficient and imperfect.

Its definition puts the weight on action, in the words actively works. An ally, in this sense, is defined by what they do, not only by what they believe.