This is the 7641st most frequent Japanese word.
動き出そ
"動き出そ" is a conjugation of "動き出す," meaning "to start moving" or "to begin to move."
In this sentence, '動き出そ' is used in its stem form to imply the transition into movement, indicating the clock is about to start functioning or rotating.
時計が動き出そうとしている。
The clock is about to start moving.
Here, '動き出そ' suggests the initiation of movement or action regarding his plan, signifying it is beginning to come to fruition.
彼の計画がようやく動き出そうだ。
His plan seems to be finally starting to take motion.
In this example, '動き出そ' is in its volitional form, employed to actively encourage starting or initiating action or progress regarding the new project.