You can tell if lime is terrible when the rind is soft or sour. The rind should be firm and bright green. You can also smell a sour, moldy aroma. It may also be wrinkly or contain spots of organic growth. The rind should be white or yellowish. If the ring is wrinkly, you should toss it.
If the lime has gone wrong, it will dry up inside. It will swell and become dull. The flesh will pull away from the peel. The lime’s rotting juice will be bitter and contain toxins.