A mountain having highأَرْكَان [i. e. sides, or angles]: (S, K:) or having strongاركان: (TA:) or inaccessible, or difficult of access, havingاركان. (Har p. 561.)
2.
And hence, (Har ibid.,) (tropical:) A man (S, K, &c.) firm, (Har,) still, or motionless, (TA,) grave, staid, steady, sedate, or calm. (S, K, Har, TA.)