Solution:

Each word has 3 consecutive letters of the alphabet-
couGHIng (GHI)
thiRSTy (RST)
DEFiant (DEF)

Solution:

SIX - 9 (IX) = S
9 (IX) - 10 (X) = I
40 (XL) - 50 (L) = X

=> SIX

Solution:

Because seven was hungry and 'seven ate nine' (7, 8, 9).

Solution:

Typewriter

Solution:

I an oxford dictionary where "arcade" comes before "because", because "because" begins with "B".

Solution:

Unquestionably

Solution:

Yes it is possible in Roman Numerals. In Roman Numerals,
9 = IX
10 = X
11 = XI

Thus by removing one from 9, you are getting 10 and by removing one from 11, you are getting 10 again.

Solution:

Tug of War

Solution:

On a sailboat (sale boat).

Solution:

Arc + tick + circle.
= Artic Circle