Some quotes from Euclid
Σημεῖόν ἐστιν, οὗ μέρος οὐθέν.
A point is that which has no part.
Γραμμὴ δὲ μῆκος ἀπλατές.
A line is length without breadth.
Ὅρος ἐστίν, ὅ τινός ἐστι πέρας.
A boundary is that which is the limit of anything.
τὸ ὅλου τοῦ μέρους μεῖζόν
the whole is greater than the part