From the same as nachar; a nostril -- (dual) nostrils.
see HEBREW nachar
H5156. nachir
[נָחִיר noun [masculine] nostril (apparently from above √, and not connected with Arabic stab camel in wind-pipe, etc., Aramaic נְחַר kill by stabbing, in nose or throat, compare Late Hebrew נָחַר perforate, kill by stabbing, so that נָחִיר would = perforation, and נחר snort would be denominative); — only dual sf עָשָׁן יֵצֵא מִנְּחִירָיו Job 41:12 (of crocodile).