"Canny" refers to being clever, astute, or showing good judgment, especially in practical matters. Someone described as "canny" is often skilled in making decisions that are sensible and advantageous. In this context, "clever" is an appropriate synonym because it captures the idea of being intelligent and resourceful.

The antonym (opposite) of the word "SCARCE" is:

(A) plentiful

"Scarce" means in short supply or insufficient, while "plentiful" means abundant or ample, making it the opposite in meaning.

The synonym for the word "COERCE" is:

(B) pressurize

"Coerce" means to persuade someone to do something by using force or threats, and "pressurize" shares a similar meaning in the context of applying pressure or influence to achieve a particular result.

The word "Strident" means loud, harsh, and grating. The antonym (opposite in meaning) for "Strident" is:

(C) Moderate

"Moderate" suggests a middle level of intensity or volume, in contrast to the loud and harsh nature of something strident.

A ruler with total power over a country, typically one who has obtained control by force.

An Achilles' heel (or Achilles heel) is a weakness in spite of overall strength, which can lead to downfall. While the mythological origin refers to a physical vulnerability, idiomatic references to other attributes or qualities that can lead to downfall are common.