up ‧ take /ˈʌpteɪk/ BrE AmE noun
[ Sense 1: Date: 1800-1900 ; Language: Scottish English ; Origin: uptake 'to understand' (18-20 centuries) . ]
[ Sense 2-3: Date: 1900-2000 ; Origin: up + take ]
1 . be slow/quick on the uptake informal to be slow or fast at understanding something
2 . [singular] the number of people who use a service or accept something that is offered:
The uptake of some vaccinations fell as the media stirred up fears of possible side effects.
3 . [uncountable and countable] the rate at which a substance is taken into the body, a system etc:
the uptake of sugars by the blood