All 4 Uses

assume
in
And Then There Were None
(Edited)

Lombard said: "I suppose that's why we assumed it must be a stranger moving about up here."
p. 137.6 *

assumed = accepted as true (without really knowing)
Now he assumed command with the ease born of a long habit of authority.
p. 148.9 *

assumed = took on (power or responsibility)
Mr. Justice Wargrave said: "You are assuming heresay to be evidence."
p. 155.5

assuming = accepting as true (without proof)
In all this, I have assumed that the mystery of Indian Island will remain unsolved.
p. 299.1

assumed = accepted as true (without really knowing)

Definitions:

(1) (assume as in: I assume it's true)
to accept something as true without proof
(2) (assume as in: She assumed power)
beginning to take power or responsibility
(3) (assume as in: She assumed a false identity)
to take on (adopt, wear, strike a pose or appearance of) -- often while pretending or disguising
(4) (assume as in: assumed into heaven)
to take up or receive someone into heaven
(5) (meaning too rare to warrant focus)