旬
xún
ten-day period, one of the three ten-day divisions of a month
HSK 79
Additional Dictionary Meanings
(bound form) ten-day period; one of the three ten-day divisions of a month (e.g. 上旬[shang4 xun2])(bound form) ten years (in age expressions, e.g. 六旬[liu4 xun2] "sixty years old")