" uptake "

[Noun]  | "up*take" | \ ˈəp-ˌtāk \

1: the act or action of grasping with the mind : understanding, comprehension —usually used in the phrases quick on the uptake and slow on the uptake

2: an act or instance of absorbing and incorporating something; especially : the absorption or incorporation of a substance into a living organism, tissue, or cell

3: the act of using, participating in, adopting, or taking advantage of an available product, service, opportunity, etc.

Origin: 1816 ;

 Scots uptake to understand;

[Idiomatic phrase]  | "take notice" 

1: to become aware of or give attention to something or someone : to observe or treat something or someone with special attention —often used with of

Origin: 1586 ;

[Noun]  | "uptake"