graduate, soldier, private, die
卒 centers on reaching an endpoint: completing a course of study (graduating), ending life (dying), or serving as a low-ranking soldier whose duty ends. The soldier sense is a specific application of a person whose role is to finish a task.
卒 originally depicted a garment with a distinguishing mark, used for soldiers' uniforms, and later extended to mean a soldier or servant. The modern form is simplified, and the connection to 'graduate' or 'die' likely developed from the idea of finishing or ending.
The top part looks like a person with arms outstretched, and the bottom 十 marks the finish line. Picture a soldier crossing the line to graduate from training, or reaching the final end.
For ソツ, imagine a soldier graduating and tossing his cap: the toss sound cues ソツ as he finishes his duty.
graduation; completion (of a course)
low-ranking soldier
graduate; alumnus; alumna
new graduate; recent graduate
please; kindly; I beg of you; if it pleases you
having graduated from high school (as one's highest completed level of education); high school graduate
stroke; cerebral haemorrhage; cerebral hemorrhage
university graduate; having graduated from university
graduation thesis; bachelor's degree thesis
having graduated from junior high school (as one's highest completed level of education); having completed no schooling beyond junior high school; middle school graduate
fainting; swooning
private (soldier); (common) soldier; ranks; rank and file
university graduate; college graduate
low-ranking prison guard
stupa; dagoba
college graduate
cerebral stroke; apoplexy
person who attended a nursery school as a child (as opposed to a kindergarten)
private; foot soldier; infantryman
private first-class