1.
deep knowledge; profound understanding; expertise
A high level of scholarly knowledge or artistic accomplishment in a particular field. Used to express respect for someone's depth of learning.
造詣 is a formal, literary word almost always used in the set phrase 造詣が深い (to have deep knowledge/expertise).
Common patterns
This word is not used in casual conversation. It conveys admiration for someone's depth of learning, particularly in academic, artistic, or cultural domains.
Note: Do not confuse with 造形 (same reading), which means "molding" or "shaping" in art.