noun which may take the genitive case particle 'no'
Describes a person or worker who lacks skill or experience, often used in professional or training contexts.
Unskilled workers need training.
He is still inexperienced, but he is motivated.
熟練 means 'skilled' or 'experienced', the opposite of 未熟練.
Compound of 未 (mi, 'not yet') + 熟練 (jukuren, 'skill, proficiency'). The exact historical derivation is uncertain, but the components clearly indicate 'not yet skilled'.