The word translated as "for" introduces a reason or explanation so "because" and, in questions, "why." However, since this word always appears in the second position, it is more like an aside remark like, "consequently" or "as a cause".  This word appears in the Greek after the verb translated as "shall it come upon" so that verb is the beginning of the sentence.

The word translated as "as" has a very broad meaning, translating as "how", "when", "where", "just as", "like," and related words. This word describes the "unforeseen day" in that verse.

"A snare" is a unique word for Jesus to use. It means "trap" and, metaphorically, "snare". It appears in the previous verse which is full of unique words.

"Shall it come on" is a Greek verb which means "come upon", "approach", and, in a hostile sense "come against", "attack". The root word is the word usually translated as "come". The sense is obviously hostile, "come against" but there is no "him" here. The form is an adjective, "attacking". This is an uncommon word for Jesus, used only two other places. It is another word that only appears in Luke. The "it" here refers to the day, which is a trap, described in the previous verse.

The word translated as "on" means "on", "over", "upon", "against", "before", "after", "during", "by" or "on." This word is repeated because it appears in the prefix of the verb above. It is repeated for emphasis.

The word translated as "all" is the Greek adjective meaning "all", "the whole", "every," and similar ideas. When it is used as a noun, we would say "everything."

The Greek word translated as "them that dwell"" means to "sit," especially of courts, councils, assemblies, etc. As a noun, which is how it is used here, it means "the judge," or "the court."  Jesus seems to use this word exclusively to refer to sitting in judgment of others. This is not the Greek word usually translated as "dwell".

The word translated as "unto" means "on", "over", "upon", "against", "before", "after", "during", "by" or "on." This is the third repetition of the word.

"Face" is the Greek word that means "face", "countenance." "in front", "facing", "front", "facade", "one's look", "dramatic part", "character", "in person", "in bodily presence", "legal personality", "person," and "feature [of the city, of a person]."  Jesus uses it to refer to facing power or the appearance of power.

"Of" comes from the form of the next two words.

The word translated as "the whole" is the Greek adjective meaning "all", "the whole", "every," and similar ideas. When it is used as a noun, we would say "everything." Though this word means "whole", Jesus usually uses a different Greek word for that concept. He usually uses this word to mean "all".

The word translated as "earth" means "ground" and "dirt". Translated as "earth", it refers to the physical planet, not society, which Christ describes using a different Greek word. This word is usually translated as "the earth" not "the world". See this article for more on these words.