All 3 Uses

allude
in
Ethan Frome
(Auto-generated)

At our next meeting he made no allusion to the book,
Chpt Open *

allusion = indirect reference
Ethan had imagined that his allusion might open the way to the accepted pleasantries, and these perhaps in turn to a harmless caress, if only a mere touch on her hand.†
Chpt 5

allusion = an indirect reference
From the beginning of the discussion he had instinctively avoided the mention of Mattie's name, fearing he hardly knew what: criticism, complaints, or vague allusions to the imminent probability of her marrying.†
Chpt 7

allusions = indirect references

Definitions:

(1) (allude)
to make an indirect reference

The expression, no allusion can mean "not even an indirect reference"; i.e., neither a direct nor an indirect reference to something.
(2) (meaning too rare to warrant focus)