in- ‘in’ + halare ‘breathe’

source: [無彩限のファントム・ワールドの和泉玲奈がファントムを吸い込むGIF画像｜無料GIF画像検索 GIFMAGAZINE 922066]

breathe in (air, gas, smoke, etc.):

｟ややかたく｠ 〈息･煙など〉を吸入する, 吸い込む(breathe in)(↔ exhale)

e.g. with object : they were taken to the hospital after inhaling fumes

(息などを)吸い込む

e.g. no object : she inhaled deeply on another cigarette.

with object North American informal eat (food) greedily or rapidly:

｟米話｠ …をがつがつ食べる, …をがぶ飲みする.

e.g. later on I inhaled a box of chocolate cookies while watching cable TV.

early 18th century: from Latin inhalare ‘breathe in’, from in- ‘in’ + halare ‘breathe’.