stamina, fortitude, potency See http://thesaurus.reference.com/browse/strength for more.
There are many words that have the same meaning as strength. A few of those synonyms are power, resilience, muscle, force, and solidity.
fitness, stamina, courage, cogency
A homophone for a deed of strength or skill is the word "feat." A homophone is a word that is pronounced the same as another word but differs in meaning, origin, or spelling. In this case, "feat" sounds the same as "feat," which means a notable or impressive act or achievement.
The word virtue comes from a Latin root meaning strength or power.
A word that has the same meaning as another word is a synonym.
Sthenic
The word in the passage with the same meaning as instantly is "immediately."
CrossFit
Some words that contain the root word "onym" are synonym (meaning a word with a similar meaning), antonym (meaning a word with the opposite meaning), and homonym (meaning a word that sounds the same but has a different meaning).
The root of the word "Democrat" comes from the Greek word "demos," meaning "people," and "kratos," meaning "rule" or "strength." So, Democrat can be interpreted as "rule of the people" or "strength of the people."
The word that has the same meaning as "opened by force" is "pry."
grit, guts