For "lawful" meaning "according to law":
* Leg-: (Latin) This is the root of "legal," so words like "legitimate," "legally," and "legislature" convey the idea of being in accordance with the law.
* Juri-: (Latin) This root refers to law and justice, so words like "jurisdiction," "jury," and "jurisprudence" relate to the legal system.
For "lawful" meaning "proper" or "right":
* Just-: (Latin) This prefix means "fair" or "rightful," so "justly," "justice," and "just" can convey a similar meaning to "lawful."
* Right-: (Old English) This prefix implies "correct" or "proper," so "rightfully," "righteous," and "right" can also be used.
For "lawful" meaning "authorized" or "permitted":
* Per-: (Latin) This prefix means "through" or "thoroughly," so "permitted" and "permission" imply that something is allowed.
* Auth-: (Greek) This prefix means "power" or "authority," so "authorized" and "authority" can be used to express legal approval.
Ultimately, the best prefix to use will depend on the specific context and the nuance you want to convey.