Half-learned refers to a situation where an individual has only partially mastered a subject or topic, lacking a full understanding and proficiency. There are several synonyms that can describe this term, such as "inexperienced," "amateurish," "ignorant," and "novice." These terms point towards the limited knowledge or proficiency in a particular field. Other synonymous words that may describe half-learned could include "unskilled," "inept," "unprofessional," or "incomplete." These words reflect on the additional need for training or learning to attain full expertise in a particular area. Overall, the synonyms for half-learned indicate an insufficient grasp of knowledge or information on a subject.