SPRINGFIELD, Mass. — Merriam-Webster, the oldest dictionary publisher in America, has turned itself into a social media powerhouse over the past few years. Its editors star in online videos on hot-button topics like the serial comma, gender pronouns and the dreaded “irregardless.” Its Twitter feed has become a viral sensation, offering witty — and sometimes pointedly political — commentary on the news of the day.

Kory Stamper, a lexicographer here, is very much part of the vanguard of word-nerd celebrities. Her witty “Ask the Editor” video contributions, like a classic on the plural of octopus, and personal blog, Harmless Drudgery, have inspired a Kory Stamper Fan Club on Facebook. One online admirer has carefully tracked minute changes in her hair (which, for one thing, is purple).

But the company remains very much a bricks-and-mortar operation, still based in this small New England city where the Merriam brothers bought the rights to Noah Webster’s dictionary in the 1840s and carried on his idea of a distinctly American language. And this month, Ms. Stamper, the author of the new book “Word by Word: The Secret Life of Dictionaries,” was more than happy to offer a tour of some of the distinctly analog oddities in the basement.