I would just like to thank AlanF for his work in providing these source for supporting JWs view as to what parousia means. Allow me to highlight in red the parts that support our belief.
One definition of parousia is the "arrival or visit of a king."
The Analytical Greek Lexicon Revised (Harold K. Moulton, Zondervan Publishing House, 1978) indicates on p. 311 that parousia is related to pareimi, which has various meanings including to be beside, to be present, to be come (p. 307). For parousia it gives the meanings presence, a coming, arrival, advent, and gives Matt. 24:3, 27, 37, 39 as examples of the latter three.
Bauer’s Greek-English Lexicon (2nd edition, 1979) says that parousia has the meanings “coming, advent as the first stage in presence” (p. 629) and gives several references to ancient Greek literature. It gives Matt. 24:3 as an example of this use “in a special, technical sense.” It says further: “The use of parousia as a technical term has developed in two directions. On the one hand the word served as a cult expression for the coming of a hidden divinity, who makes his presence felt by a revelation of his power, or whose presence is celebrated in the cult… On the other hand, parousia became the official term for a visit of a person of high rank, especially of kings and emperors visiting a province… These two technical expressions can approach each other closely in meaning, can shade off into one another, or even coincide.”
Liddell & Scott’s Greek-English Lexicon (p. 1343) gives “Advent” as the meaning in each instance in Matthew.
Expository Dictionary of Bible Words (Lawrence O. Richards, Zondervan Publishing House, 1985, p. 65) says of parousia that “the word means ‘presence’ or ‘coming’ and emphasizes both the idea of ‘being there’ and the idea of ‘having come.’ . . . Parousia is found four times in the Olivet Discourse (Mt 24:3,27,37,39). The context makes it clear that Jesus’ initial appearing is intended, for the disciples asked how they would recognize the sign of his coming. Jesus explains that he will appear suddenly (v. 27), unexpectedly (v. 37), and with devastating impact on those who do not believe (v. 39). Yet the emphasis in the total passage (Mt 24–25) is not on the meaning of the second coming but on the fact that, until Jesus does come, we are to watch, committing ourselves to serve our absent Lord (cf. the four illustrations in Mt 24:42–25:46).”
Thayer’s Greek-English Lexicon (p. 490) gives Matt. 24:3 as an example of the meaning “the presence of one coming, hence the coming, arrival, advent.”