As a noun carus
is (medicine) coma with complete insensibility; deep lethargy.
As a verb crus is
.
carus
English
Noun
(medicine) coma with complete insensibility; deep lethargy
(
Webster 1913)
----
crus
English
Etymology 1
.
Noun
(crura)
The lower leg.
A leglike part; shank.
Etymology 2
Noun
(head)