A pair of keets or parakeet.
leftovers
j+s+k
The rebus puzzle "X over TOAST" represents the phrase "cross toast," which sounds like "crossed." The "X" symbolizes "cross," and "TOAST" is the literal word. Therefore, the answer to the rebus is "crossed."
head over heels
mind over matter
Escape on foot.
The term "KEET-KEET" is not a recognized brain teaser or puzzle in the traditional sense. Without further context or information, it is difficult to provide a specific answer to what it means in that context. It is possible that "KEET-KEET" could be a made-up or nonsensical phrase used as part of a riddle or puzzle, but without additional details, its meaning remains unclear.
A rebus.
taken over
The word "puzzle" itself is six letters. Two six-letter synonyms for puzzle are "enigma" and "riddle".
Rebus
It.