inhalation
n. C / U C1 Advanced US //ˌɪnhəˈɫeɪʃən// UK //ɪnhɐlˈeɪʃən// in·hala·tion
n. the act of breathing air or other substances into your lungs.
n. the process of drawing air, smoke, or other vapours into the lungs through the respiratory tract.
The doctor told him to take a deep inhalation.
Workers in the factory must wear masks to prevent the inhalation of harmful chemical dust.
The rapid onset of the drug's effects is due to its delivery via inhalation, which allows the active compounds to enter the bloodstream almost immediately through the pulmonary capillaries.
From inhale + -ation.
Usage
Uncountable when referring to the general process; countable when referring to a single instance of breathing in.