1. Marked by deception
   - underhand, underhanded 
2. Marked by quiet and caution and secrecy; taking pains to avoid being observed
   - furtive, sneak, stealthy, surreptitious

Derived forms: sneakier, sneakiest

See also: bent [Brit], concealed, corrupt, crooked, sneak, sneakily, sneakiness

Encyclopedia: Sneaky

• family Hadrosauridae
• family Haematopodidae
• family Haemodoraceae
• family Haemoproteidae
• family Haemulidae
• family Halictidae
• family Haliotidae
• family Haloragaceae
• family Haloragidaceae
• family Hamamelidaceae
• family Helicidae
• family Helodermatidae
• family Helotiaceae
• family Helvellaceae
• family Hemerobiidae
• family Hemerocallidaceae
• family Hemiprocnidae
• family Hemiramphidae
• family Heteromyidae
• family Hexagrammidae
• family Hexanchidae
• family Hippoboscidae
• family Hippocastanaceae
• family Hippopotamidae
• family Hipposideridae