Language Of Confusion: Tense, Part V

 
 
Here’s the last part of the series looking at words related to tense—there are more, words that end in -tend, but I did those fairly recently, so we won’t be looking at them. These words, all from the Proto Indo European root ten-, to stretch, all end in -tain.
 
First, abstain showed up in the late fourteenth century, coming from the Old French abstiner/abstenir. That’s from the classical Latin abstinere, which of course is just to abstain. The ab- means of or away from, and the rest is from tenere, to hold, from ten-. Which I’ve probably mentioned during every one of these posts. Anyway, to abstain is to hold down, which does kind of fit. Even the ten- to -tain makes sense.
 
Contain showed up in the fourteenth century, from the Old French contein and its verb form contenir, to hold together. The prefix is from com, with or together, and the rest is tenere. Wow, that one makes even more sense.
 
Detain showed up in the early fifteenth century, from the Old French detemir, from the classical Latin detinere, which means to detain, or more literally, to hold back. De- means from or away, so to detain is to hold away. Yes, if you’re detaining something, you’re holding it away.
 
Then we have retain, which showed up in the late fourteenth century (funnily enough, a few decades after that, people started using it to mean hold back or restrain, which was then dropped, while its original meaning is basically what we use it as today). It’s from the Old French retenir, from the classical Latin retinere, to retain or to hold back. The re- means back here, so to retain is to hold back.
 
Finally, sustain. It showed up in the late thirteenth century meaning to provide the necessities of life to, then to give support to or to keep up, then in the legal sense in the fifteenth century. It’s from the Old French sostenir/sustenir, and classical Latin sustinere, to support or hold up. The sus- is from sub-, below, so to sustain is to support something from below.
 
Look, sometimes you have things like temple or thin, and other times they just follow a sensible logic. It happens even in etymology.
 
Sources
Online Etymology Dictionary
Google Translate
Omniglot
University of Texas at Austin Linguistic Research Center
University of Texas at San Antonio’s page on Proto Indo European language