If you think about it, abject ("miserable"), object ("thing"), inject ("to push into"), deject, ("depress") and reject ("dismiss") all share the same Latin root: what went into English as ject came from Latin as the verb iacere, which meant "to throw". It all makes perfect sense if you think about it. Ab- means "away from" (from the PIE root apo, "away"), and something miserable is meant to be thrown away. The same logic applies for deject: de- (of Etruscan origin) means "down" and you can definitely makes someone depressed by throwing them down figuratively. Re- (from PIE wret, "to turn") means "back", and throwing something back is the ultimate sign of rejection. When you inject something, you're pushing it in (yes, in- the prefix, which derives from PIE en, means "in", obviously), and it's only a bit of a stretch to say you're almost "throwing" it in. Object is the strangest of the five and has developed the most: ob- (from PIE opi, "against") was the Latin prefix for "against". Something against which stuff is thrown is a target, and a "target" was exactly what the original definition for object was; later it developed to mean "stuff" in general and singular. Now that we know all that, iacere is from the Proto-Italic word jajko, from Proto-Indo-European hyeh. Both terms meant "to throw". How interwoven our language is!
Adam Aleksic, a leading contender for valedictorian of his high school, is a 210-month-old boy with disturbing interests in etymology, vexillology, geography, and law. Adam would like to one day visit Tajikistan and probably isn't spying for the Kyrgyz government.
The Etymology Nerd