What part of word carries the burden of its meaning?
the root of the word carries the burden, the prefix or suffix alters that meaning.
A word part is basically a couple of simple letters such as in, un, de. The simple use of putting the word part "un" in front of words completely changes the meaning to the opposite. ie. Something necessary becomes unnecessary, usual to unusual. Thereby simply adding a wordpart can completely change the meaning of a word.
There are two parts to this word. The first part, recta, means "right" or "correct," and is describing a feminine noun. The second part, que, is an enclitic meaning "and." So, the meaning of rectaque is "and right" or "and correct." It has to be with the corresponding noun, though, to make sense as a word.