Noun
An
alkaloid
,
C
<
sub
>
8
sub
>
H
<
sub
>
10
sub
>
N
<
sub
>
4
sub
>
O
<
sub
>
2
sub
>,
found
naturally
in
tea
and
coffee
plants
,
which
acts
as
a
mild
stimulant
on
the
central nervous system
.