D2E1C3E1N1N1I1A1L1
12 points
DECENNIAL is validvalid
an event that occurs every ten years [n DECENNIALS]
happening every ten years [adj DECENNIALLY] / a ten-year anniversary [n -S]
an event that occurs every ten years [n DECENNIALS]
happening every ten years [adj DECENNIALLY] / a ten-year anniversary [n -S]