Sheila Michaels, who half a century ago, wielding two consonants and a period, changed the way modern women are addressed, died on June 22 in Manhattan. Ms. Michaels, who introduced the honorific “Ms.” into common parlance, was 78.

The cause was acute leukemia, said Howard Nathanson, a cousin.

Ms. Michaels, who over the years worked as a civil-rights organizer, New York cabdriver, technical editor, oral historian and Japanese restaurateur, did not coin “Ms.,” nor did she ever claim to have done so.

But, working quietly, with little initial support from the women’s movement, she was midwife to the term, ushering it back into being after a decades-long slumber — a process she later described as “a timid eight-year crusade.”

“Apparently, it was in use in stenographic books for a while,” Ms. Michaels said in an interview for this obituary in 2016. “I had never seen it before: It was kind of arcane knowledge.”