pant, gasp, breathe hard
喘 centers on labored, audible breathing: panting, gasping, or breathing hard, often from exertion or distress.
喘 combines 口 (mouth) with 耑, which likely contributes the sound and may relate to rapid or short movement, fitting the idea of quick, labored breaths.
The mouth 口 is open, and the right side 耑 looks like a sprout pushing up with effort. Picture someone breathing hard after a sprint, mouth open and chest heaving like a struggling plant.
For ゼン, imagine a zen monk trying to meditate, but he's out of breath from running: zen -> ゼン, and he's panting with his mouth open.
to gasp; to pant; to breathe hard
asthma
gasping; puffing; wheezing
stridor; wheezing; noisy breathing
aspirin-induced asthma; aspirin-exacerbated respiratory disease
lingering life; feeble existence; brink of ruin
to be overanxious; to worry needlessly
gasping; breathing heavily
panting; gasping; heavy breathing
to have an attack of asthma
asthma attack; asthma exacerbation
stridor
infantile asthma
death rattle
the remainder of one's life
bronchial asthma