The New Testament was written in Greek, and many Old Testament terms have their bridge in the Greek terms of the septuagint. Analyzing the term "theos" would not even be important, if it weren't for people who, due to the lack of knowledge of the term, invent dark constructions on the term. Thus knowledge becomes necessary because of the inventions created, which have no commitment to the truth.
To begin with, the term "theos", which forms the term god in Greek, is not the same as the term god, from the Latin. So all definitions that use the radical in Greek are not Latin. For example, Zeus, is a Greek term, so god of the Latin term does not come from the term Zeus. Not even the term god in Greek comes from Zeus, but the opposite, which is logical. The definition of something, exists before its description.
A blue house must have the Blue definition, before the house. In ancient Greek culture Zeus was defined as a god, so first comes the definition of god, and then comes the term Zeus. Even so, the Latin term for God does not come from the Greek god.
What we have is that the term "theos", can come from the term "to give", or "to receive", in this case a blessing, or to claim and to receive. What is clear is that "theos" has a connection with asking and receiving, fundamentally in that god, is the giver of something. In fact, in Greek culture, the gods grant things to humans, as if they were donors.
We could say that the term god in Greek, would define the donations of higher beings, and the god in Latin, represents the location of the entity, or its celestial characteristic. Anyway, the term "god" does not come from Zeus, neither in Greek nor in Hebrew. In fact the term god, describes information about the entity.
For example, to say that Zeus is god, in Greek, would possibly represent that Zeus grants things to the man who worships him. To say that Zeus is god, in Roman, would define that Zeus is a celestial entity. In any case, the term god did not come from the term "Zeus".
Yet the correct origin of the term "theos", the Greek etymology of the word god, is very difficult to say. But we can clearly say that the term represents a characteristic for the noun that we link that term to.