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The length of the arm measured from top of the clavicle to the tip of the middle finger, with the arm straight down at the side of the body.
The noun has one meaning: a distance sufficient to exclude intimacy
at arm's length
At a distance, avoiding intimacy or familiarity, as in Bill hated seeing his colleagues outside the office, preferring to keep all of them at arm's length, or She was friendly only when he was safely at arm's length. Now often used with the verb keep, this term for distancing oneself from a person, organization, or issue originated as at arm's end but developed its current form by the mid-1600s.
English term or phrase: "at arms' length" Loans and Guarantees – No employee or officer (or their immediate family member) may accept loans or guarantees of obligations (except from banks of other entities that provide such services in the normal course and at arms’ length) from any individual, organization or entity doing or seeking to do business with the Company.