[see also: answer, solution, explication]
The explanation for this definition is that ......
This corollary calls for some explanation and comment.
A formula like (3) surely deserves some explanation.
a lucid $\langle$clear/plausible/likely/straightforward$\rangle$ explanation
Go to the list of words starting with: a
b
c
d
e
f
g
h
i
j
k
l
m
n
o
p
q
r
s
t
u
v
w
y
z