assistant, help
佐 centers on providing support or aid: an assistant who helps someone in a secondary role.
佐 combines 亻 (person) with 左, which likely contributes both sound and the idea of assisting from the left-hand side.
A person 亻 standing beside 左 (left) suggests a helper who supports from the side, like a left-hand assistant.
For サ, imagine an assistant named Sa helping from the left: Sa -> サ, and the person 亻 beside 左 is always ready to help.
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Saga (city, prefecture)
colonel; (navy) captain
major; lieutenant commander; wing commander
aid; help; assistance; assistant; counselor; counsellor; adviser; advisor
lieutenant colonel; commander (navy)
Tosa (former province located in present-day Kochi Prefecture)
Sado (former province located on Sado Island in present-day Niigata Prefecture)
Sagawa Express (parcel delivery company)
Susanoo (deity, younger brother to Amaterasu); Susanoo-no-Mikoto
chicken grunt (Parapristipoma trilineatum); threeline grunt
tosa (dog breed)
field officer
colonel (JASDF, JGSDF); captain (JMSDF)
captain (JMSDF)
colonel (JASDF)
colonel (JGSDF)
major (JGSDF)
lieutenant-commander (JMSDF)
major (JGSDF)
lieutenant colonel (JGSDF)