1. Conducted with or marked by hidden aims or methods
   "an undercover investigation"
   - clandestine, cloak-and-dagger, hole-and-corner, hugger-mugger, hush-hush, secret, surreptitious, underground

See also: covert

Encyclopedia: Undercover

• ineffectually
• ineffectualness
• emplastic
• employ
• employable
• employe
• employed
• employee
• employee ownership
• employee savings plan
• employee stock ownership plan
• employee turnover
• employee-owned business
• employee-owned enterprise
• employer
• employment
• employment agency
• employment agent
• employment agreement
• employment contract
• employment interview
• employment office
• emporium
• empower
• empowered