词根词缀：-enni-, -ennial, -ennium

【来源及含义】Latin: year, years

【同源单词】aere perennius, amillennialism, annual, biannual, bicentennial, biennia

词根词缀：sex-, sexi-, sext-

【来源及含义】Latin: six, sixth; a word element for number 6

【相关描述】Don't confuse this sex- with another one that refers to "mating" or "gender".

【同源单词】senary, sexadecimal, sexagenarian, sexagenary, sexagesima, sexagesimal