1. having no flavor; bland
2. showing poor judgment about what is appropriate or attractive; lacking good taste

Examples

• The soup was completely tasteless and needed more seasoning.
• She found the hospital food bland and tasteless.
• His tasteless joke offended everyone at the dinner party.
• The decorations were colorful but tasteless.
• It was tasteless of him to mention money at the funeral.
• The movie was criticized for its tasteless humor.
• The crackers were dry and tasteless without any toppings.