"Straight" in every sense: direction, morality, and law
Encoding Strategies:
linguistic

direct
straight
+
-o
suffix
Derecho means straight and is a cognate of direct0 — both share the core idea of being straight or lined up0.
derecho
straight, upright (not bent or curved)
Going or standing in a straight line, without bending or veering.
Este árbol ha crecido completamente derechoThis tree has grown completely straight
Camina derechoWalk upright / straight
right, right-hand (direction)
The right side of the body — historically the "straight" or "strong" side, as opposed to the left side.
El futbolista se lastimó el pie derechoThe soccer player injured his right foot
Tuerza por la primera a la derechaTurn at the first right
honest, upright, straight (morally straight)
A person who is morally "straight" is honest and upright.
Mi vecino es un hombre derecho y humildeMy neighbor is an honest, humble man
right, entitlement (an entitlement)
A right or entitlement — what is "straight" or correct that someone may legitimately claim or do.
Todos los niños tienen derecho a la educaciónEvery child has the right to an education
Están en su derechoThey are within their rights
law (the field of law)
The body of rules and principles that define what is straight / correct in society.
Mi hijo va a estudiar derechoMy son is going to study law