Kangaroo word: weakening
Joey word: waning
Definitions in relation to their use in kangaroo words, taken from Google Dictionary, and edited for formatting.
weakening (verb): make or become weaker in power, resolve, or physical strength.
waning (verb): decrease in vigor, power, or extent; become weaker.
The letters W, A, N, I, N, and G found within the kangaroo word “weakening” arrange in the listed order to complete the joey word “waning”. While a word can have multiple definitions, in relation to their use with kangaroo words, these two words share a similar meaning: become weaker.