DEVILISH
devilish, diabolic, diabolical, mephistophelian, mephistophelean
(adjective) showing the cunning or ingenuity or wickedness typical of a devil; “devilish schemes”; “the cold calculation and diabolic art of some statesmen”; “the diabolical expression on his face”; “a mephistophelian glint in his eye”
devilish, rascally, roguish
(adjective) playful in an appealingly bold way; “a roguish grin”
devilishly, devilish
(adverb) in a playfully devilish manner; “the socialists are further handicapped if they believe that capitalists are not only wicked but also devilishly clever”
Source: WordNet® 3.1
Etymology
Adjective
devilish (comparative more devilish, superlative most devilish)
Resembling a devil.
Characteristic of a devil.
(informal) Extreme, excessive.
Synonyms
• (resembling a devil): atrocious, demoniac, deuced, diabolic, evil, fiendish, ghoulish, malicious, mischievous, nefarious, ogreish, reprobate, unhallowed, wicked
• (characteristic of a devil): demonic, diabolic, diabolical, hellish, infernal, satanic, satanical
• (extreme): excessive, extreme.
Adverb
devilish (comparative more devilish, superlative most devilish)
(informal) Devilishly; very; exceedingly.
Source: Wiktionary
Dev"il*ish, a.
1. Resembling, characteristic of, or pertaining to, the devil;
diabolical; wicked in the extreme. "Devilish wickedness." Sir P.
Sidney.
This wisdom descendeth not from above, but is earthly, sensual,
devilish. James iii. 15.
2. Extreme; excessive. [Colloq.] Dryden.
Syn.
– Diabolical; infernal; hellish; satanic; wicked; malicious;
detestable; destructive.
– Dev"il*ish*ly, adv.
– Dev"il*ish*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition