来自拉丁语 summa,阴性形式于 summus,最高的，最上面的，缩写自 PIE*sup-mos-,最上面的， 构成 super 的最高级形式，-m,最高级后缀，词源同 maximum,minimum.后形容词作名词使用， 引申词义最高点及相关词义。
英文词源
sum
sum: [13] Latin summus meant ‘highest’ (a meaning preserved in English summit [15], which is ultimately derived from it); it evolved from an earlier *supmus, a superlative form based on the stem of Latin super ‘above’ (source of English super). When the Romans counted up columns of figures they worked from the bottom upwards, and put the total on top – whence the use of the expression rēs summa, literally ‘highest thing’, for ‘total’. This was eventually shortened to summa, which reached English via Old French summe. Other derivatives in English include consummate [15] and summary [15]. => consummate, summary, summit
sum (n.)
c. 1300, summe, "quantity or amount of money," from Anglo-French and Old French summe, somme "amount, total; collection; essential point; summing up, conclusion" (13c., Modern French somme), from Latin summa "the top, summit; chief place, highest rank; main thing, chief point, essence, gist; an amount (of money)," noun use (via phrases such as summa pars, summa res) of fem. of summus "highest, uppermost," from PIE *sup-mos-, from root *uper "over" (see super-).
The sense development from "highest" to "total number, the whole" probably is via the Roman custom of adding up a stack of figures from the bottom and writing the sum at the top, rather than at the bottom as now (compare the bottom line).
General sense of "numerical quantity" of anything, "a total number" is from late 14c. Meaning "essence of a writing or speech" also is attested from mid-14c. Meaning "aggregate of two or more numbers" is from early 15c.; sense of "arithmetical problem to be solved" is from 1803. Sum-total is attested from late 14c., from Medieval Latin summa totalis.
sum (v.)
early 14c., "to count, count up, calculate, reckon," from Old French sommer "to count, add up," or directly from Medieval Latin summare, from summa (see sum (n.)). Meaning "briefly state the substance of" is first recorded 1620s (since c. 1700 usually with up). Related: Summed; summing.
实用例句
1. The sum of evidence points to the crime resting on them.
所有证据都表明该犯罪乃他们所为.
来自柯林斯例句
2. What are you doing fooling with such a staggering sum of money?
你拿着这么一大笔钱瞎折腾什么呢？
来自柯林斯例句
3. You owe a certain person a sum of money.
你欠某人一笔钱。
来自柯林斯例句
4. The guests had each paid £250, no trifling sum.
客人每位付了250英镑，可不是一笔小数目。
来自柯林斯例句
5. The sum of all the angles of a triangle is 180 degrees.
