A headline on Google News today, attributed to the BBC, reads,
Grenfell Tower fire: Minute’s silence marks one-year anniversary
Apparently somebody got to the BBC, though, because the web site now shows this headline:
Grenfell Tower fire: Silent walk marks first anniversary
The word anniversary already includes the concept of a year. It comes from Latin annus (= a year) and versus, past participle of verto (= to turn), and means [the day] of the turning of a year. To add “year” to it is like saying “your birthday day”.
I keep reading, though, of “one-year” and “ten-year” anniversaries. Maybe people have started adding “year” to anniversary because of the even stupider practice of celebrating “one-month” and “six-month” and suchlike “anniversaries”.