River Trent.
Groot River in south Africa
Tagus
There doesn't seem to be one. It seems to be discussing a body of water, but nothing seems to fit. Brook (5 letters) Creek (5 letters) River (5 letters) Stream (6 letters) "A stream" is 7 letters, but that is 2 words and has a space.
A striped animal that has a name that is 5 letters long is the zebra. Another striped animal with a name that has 5 letters is the tiger.
The Huge star name with 3 and 5 letters is the Red Giant.
It's hilarious how your name is in that method with 6 letters for the first name, 5 for the last name but if you need name ideas, just ask for them online.
tulip
Cobra
There are total of 5 letters in Mario
Craig David. David Bowie.
The South American nation of Chile has a name with 5 letters.
hedge