This is the 16438th most frequent Russian word.
рукав
Sleeve.
Here, 'рукав' refers to the sleeve of a garment, an essential part of clothing terminology.
На его рубашке порвался рукав.
The sleeve of his shirt tore.
In this context, 'рукав' is used to represent a channel or a branch of a river, showing its geographical usage.
Река разветвилась, образуя широкий рукав.
The river branched out, forming a wide channel.
This usage of 'рукав' again refers to the sleeve of a coat, illustrating practical usage in everyday scenarios.