General:
* Mouth: This is the most general synonym, referring to the entire opening.
* Edge: This works when talking about the edge of something.
* Rim: Similar to edge, but emphasizes a curved edge.
* Border: Similar to edge and rim, but can be used more broadly.
Specific to speaking:
* Mouthe: This is a more poetic and archaic synonym.
* Chops: This is a slang term, often used humorously.
* Kissers: Another slang term.
Specific to physical appearance:
* Pout: This refers to the shape of the lips when someone is pouting.
* Cupid's bow: This refers to the shape of the upper lip.
* Full lips: Describes lips that are considered attractive.
* Thin lips: Describes lips that are considered thin.
The best synonym for "lip" will depend on the specific context of your sentence.