Sentence:  Another example of Smilla's advantageous mindset is her remembered Inuit understanding of space as she recalls measuring journeys she took with her mother in <WSD>siniks</WSD>, the number of sleeps that a journey requires (278). 
Meaning of the word marked with <WSD> tags:  The amount of distance that one can travel in a day given the current terrain and conditions, a measurement used by the native peoples of Greenland.