This is the 450th most frequent Hindi word.
मछल
The Hindi word "मछल" appears to be incomplete or misspelled. If you mean "मछली" (machhli), its definition is "fish."
Here, 'मछल' is used to refer to a specific fish, as the subject of the sentence.
मैंने नदी में एक सुंदर मछल पकड़ी।
I caught a beautiful fish in the river.
'मछल' refers to fish in general, where it describes the living habitat of the creature.
मछल जल में रहती है।
The fish lives in water.
In this sentence, 'मछल' refers to a specific fish, where it is the object of the action.