English definition of “solid”
HARD/FIRM › hard and firm without holes or spaces, and not liquid or gas: solid ground solid food
STRONG › strong and not easily broken or damaged: solid furniture
solid gold/silver/wood, etc › gold/silver/wood, etc with nothing added: a solid silver bracelet
TIME › continuing for a period of time without stopping: The noise continued for two solid hours/two hours solid.
INFORMATION [always before noun] › Solid information, proof, etc is based on facts and you are certain that it is correct: This provides solid evidence that he committed the crime.
PERSON › honest and able to be trusted solidity
/səˈlɪdəti/ noun [U] solidly adverb