suffix
seeming; appearing; looking like
Attaches to adjective stems and some nouns to express an outward appearance or impression. Often used in literary or descriptive contexts.
彼は悲しげな顔をしていた。
He had a sad-looking face.
彼女は自信ありげに話した。
She spoke with an air of confidence.
そう is a more common and colloquial suffix for 'seeming' or 'looks like', while げ is more literary and often describes a subtle or outward impression.
Derived from the kanji 気 (ki, 'spirit; mood'), used as a suffix to indicate an appearance or air of something. The kana form げ became standard for this suffix.