Now I am checking a TOEFL iBT test pages and we must choose one correct answer among 4 choices that fits in the most similar way with the meaning of the word in the question.
And I stumbled upon the question about "allude to".
The choices are
a : to ask casually
b : to refer to casually
c : to refer to formally
d : to refuse always
Now, here I am struggling to understand why "b" is the correct answer.
Merriam Unabridged says,
to have or make indirect reference (as in passing or by suggestion) : refer indirectly — used with to
So, in general (for native speakers), isn't there any chance that this verb "allude to" to be used in formal situations?
Thank you so much in assistance and in advance.