Definitions:

1. Doing something without achieving any gain, benefit, or profit. ADVERB
   • The employees protested gainlessly, as the management refused to address their concerns.
2. Engaging in activities that do not produce financial or material advantages. ADVERB
   • The business operated gainlessly for months before closing.
3. Performing an action that yields no tangible or intangible rewards. ADVERB
   • He worked gainlessly on the project, as it was eventually scrapped.

Synonyms:

• fruitlessly
• ineffectively
• pointlessly
• unprofitably
• without success