dieser meaning and definition in german

See dieses and dies for the use of these two variants of the nominative/accusative neuter.
Unlike English “this”, German dieser is not necessarily restricted to what is close to the speaker. The pronoun is indeed more likely to be used referring to something close, but it is by no means uncommon to say, for example: Siehst du diesen Turm da hinten am Horizont? Literally: “Do you see this tower back there at the horizon?”