While discussing machoz, we mentioned Klein's theory that it is a derivative of the root אחז. This is a common root in Biblical Hebrew, generally with the meaning of "to seize", "to hold" or "to grasp". (Steinberg goes further and connects a number of other roots beginning with אח meaning "connecting two things", such as אחד - "to unite, one", and אח - "brother".) From אחז we get a number of familiar words and phrases:
- achuza אחוזה - "possession, property, estate, mansion"
- ma'achaz מאחז- "stronghold, outpost" (I won't get into the political ramifications of the difference between the above two)
- beit achiza בית אחיזה - "handle, hold" (noun)
- achizat eynayim אחיזת עיניים - "deceit, delusion" (literally, "closing of the eyes", not letting the viewer see what is really happening. See the Mishna, Sanhedrin 7:11).
The word actually comes from this week's parasha, Matot. We find a description of how the spoils of war should be distributed, with the soldiers and civilians each taking one half, and then 1/500th of the soldiers' take goes to the high priest, and 1/50th of the civilian share goes to the Levites. That levy is described in Bamidbar 31:30
וּמִמַּחֲצִת בְּנֵי-יִשְׂרָאֵל תִּקַּח אֶחָד אָחֻז מִן-הַחֲמִשִּׁים, מִן-הָאָדָם מִן-הַבָּקָר מִן-הַחֲמֹרִים וּמִן-הַצֹּאן--מִכָּל-הַבְּהֵמָה
And from the half-share of the other Israelites you shall take one seized (achuz) from every fifty human beings as well as cattle, donkeys and sheep - all the animals;
The same usage of achuz appears in Divrei Hayamim I 24:6. From here, the word was reinvented in modern Hebrew, apparently by the rabbi and linguist Zeev Yavetz, as "rate, proportion" (although this article finds an earlier usage), and percentage was created as achuz l'mea אחוז למאה - "a portion of 100". This is the usage described by Ben Yehuda - I'm not sure why they didn't use the biblical "achuz m..." אחוז מן, but rather "achuz l...". As time went on, I suppose with global mathematics becoming more integrated in Israeli culture, achuz began to be used on its own, meaning only "percentage" - 1 of 100. (Interestingly, Klein, whose dictionary was compiled in the 1960s or 1970s, doesn't mention the modern usage, only the sense that Ben Yehuda described.)
The Hebrew Wikipedia article for achuz points out that achuz should only be used for a specific number (e.g. achuz echad אחוז אחד 1%, shelosha achuzim שלושה אחוזים 3%). But if one wants to say percentage in general, as in "the percentage of students who passed the test has increased", the word shiur שיעור, should be used instead of achuz.