To intend or aspire to (aim for a goal, profession, or ideal); to set one's sights on something. Often somewhat literary.
彼は将来医者を志して医学部に入った。
He entered medical school aspiring to become a doctor in the future.
幼いころから画家を志していたが、今は別の仕事をしている。
He had aspired to be a painter since childhood, but now works in a different job.
彼女は国際弁護士を志す若手だ。
She is a young person who aspires to be an international lawyer.