The word "Caucasoid" is a cognate that surges from the adjective "Caucasian" and refers to an individual of the white race. The word, as it is put in this question, is not used with the purpose of scientific classification. The meaning behind the word "Caucasian" is complicated, though. It literally refer to someone who is an ancestor or a descendant of the race group that supposedly originated in the two ranges of the mountains of Caucasus. This composes a strip of land that separates the Black Sea from the Caspian sea. The suffix "-oid" is not as widely-used in the scientific sense because its Greek origin, verbatim, is "-oeides", from "eidos" which means "form", or in modern terms, "a kind of.." Therefore, let's stick with "Caucasian" for the sake of the answer. By the way, the Caucasus can be located on a map in modern day Chechnya.
The selection of the word "Caucasian" as an anthropological descriptor for 50 particular races of a similar ethnic origin, is the work of Johann Friedrich Blumenbach back in the 18th century. It is he, and a few others who decide to connect the Caucasus to people of the white race. The evidence for the geographical origin of what is described as a "Caucasian" is still a subject of intense research, and the use of the word, itself, has became accepted, but reduced to, merely a historically-based descriptor since the 19th century.
This being said, one cannot ascertain that there will be specific features that will always be present in a person that is identified as a Caucasian. One must really look at the most recent research in this area to come to an un-biased, objective, and research-based answer to what features to expect in any given racial or ethnic group. It is just one of those topics that will always dangle on a very thin line.
What is typically accepted as fact is that, however wrong the term "Caucasian" may be, a person of this racial group has lighter features in terms of the color of the skin, hair, and eyes. That is already an overstatement because we know that not all people with white skin have light-colored eyes and hair. We also know that not every white person would fit the same stereotype.
However, what we could conclude is that in the modern sense of it, the Caucasian is the opposite of a person whose racial origin is either "African American" (another loosely used term), Asian, or Hispanic. That is about the closest approximation that we can give to a well-fit description.
The word "caucasoid" can be used as a noun or as an adjective. As a noun, caucasoid is another way of describing or naming someone of the caucasian race. As an adjective, it is a way of identifying features of persons of the caucasian race.
Therefore, the features of a caucasoid person are the same as the features of the caucasian race. To most casual observers, Caucasians are most immediately identified by their generally lighter colored skin due to a lesser amount of the melanin skin pigment.
Historically, the caucasian people originate in the geographic area of the Caucasus Mountains. Their descendants are frequently grouped based on language groupings: the native Caucasian languages; the Indo-European languages; the Mongolic language; the Semitic languages; and the Turkish languages.