oxygen deficiency; anoxia

mountain climbing

sourness (quality or condition) / (chemistry) acid

lack, shortage / to be absent / vacancy

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

sour / (chemistry) acid

Alternative spelling of 酢 (“vinegar”)

(law) lack