What is the meaning of Flien?

so-and-so, that bloke; a placeholder for a person whose name one cannot or does not want to mention, as in the phrase; "wieħed flien".

somebody, anybody

To fly; to travel in the air.

To move in the sky.

To travel with alacrity or haste; to rush.

To shoot or burst; to move rapidly.

To fall or sink; to move rapidly down.

To proliferate; to be disseminated.

To attack one's quarry or prey.

Source: wiktionary.org