ГНОЙ _|_ PUS / GNOY [ɡnoɪ̯] // ГНИЕНИЕ _|_ ROTTING / GNIENIE [ɡnʲɪˈjenʲɪɪ̯ə]     

Hint with an alternative definition: It is like a gleet that annoys you — a mark of a bad wound and stagnation, when wound «goes north» (white pus & cold of death) without hygiene (like pus while gangrene)

Hints with translations, synonyms + context — translation + consonant words (by sounds or letters): go bad > go gnaw to a nit & dung- гнить / gone & nil – гниль

Hints with anagram + context: decay at night

Hint with a mirror: young liquid | гной (old liquid, bad)

Mental visualization: ГН (bandaged wound) + O (leaked pus) + Й (new bandage) / Г (foot) + H (frozen hands) + И (leg bent at the knee) + EH (chest and hips) + ИЕ (arm and ribs)