Both Uses

yield
in
The Child by Tiger
(Auto-generated)

"No'm" — again and again, sullen and unyielding; until finally the exasperated mistress threw her hands up in a gesture of defeat and said: "All right then, Pansy.†

unyielding = strict, firm, or hard (not giving in, not giving way, or not giving up)

standard prefix: The prefix "un-" in unyielding means not and reverses the meaning of yielding. This is the same pattern you see in words like unhappy, unknown, and unlucky.
And the reason for this is that it comes to people in the South not as the grim, unyielding tenant of the Winter's keep, but as a strange and wild visitor from the secret North.†
*

Definitions:

(1) (yield as in: will yield valuable data)
to produce (usually something wanted); or the thing or amount produced
(2) (yield as in: yield to pressure)
to give in, give way, or give up
(3) (meaning too rare to warrant focus)