词根词缀：bi-, bin-, bino-, bis-

【来源及含义】Latin: two, twice, double, twofold; a number; it normally functions as a prefix

【相关描述】This bi- is used before s, c, or a vowel. Don't confuse this bi- with another one which means "life".

All words except biennial referring to periods of time and prefixed by bi- are potentially ambiguous. Since bi- can be taken to mean either "twice each" or "every two", a word like "biweekly" can be understood as "twice each week" or "every two weeks".

【同源单词】biacid, biangular, biannual, biannual, biarchy, biarticulate

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：milli-, mille-, mill-, mili-

【来源及含义】Latin: thousand; a decimal prefix used in the international metric system for measurements; including, thousandth, thousandths

【相关词根词缀】 Related "metric" families: yotta; zetta; exa; peta; tera; giga; mega; kilo; hecto; deka; deci; centi; micro; nano; pico; femto; atto; zepto; yocto.

【同源单词】bimillennium, mile, mileage, millefiori, millenary, millennial

词根词缀：-um

【来源及含义】Greek > Latin: a suffix that forms singular nouns

【相关描述】Here are just a few of the hundreds of words that end with -um.

【同源单词】abandum, abortorium, absorption spectrum, acropodium, actinium, acute delirium