the best in …; the most in …

one, 1 / first, foremost / group / entirely, wholly / other / merely, only

(neuroscience) neurotransmitter

radioactive material

the basics, a general idea

one day, 24 hours / the daytime, the period from dawn until dusk / (figuratively) a short period of time / one day, someday, an unspecified day / the first day of the month

(literally) one side / everywhere, all around, the whole area / one viewpoint, one opinion or way of thinking / the front page of a newspaper

for the time being, for the present

Panax ginseng (Chinese ginseng)

pentathlon