archarch3 adjective 
‘I think he’s in for a surprise,’ Ian said, in a somewhat arch tone.—archly adverb
WORD ORIGINarch3
Origin:
1500-1600 arch- in such combinations as arch-rogue and arch-villainEXAMPLES FROM OTHER DICTIONARIES
- an arch tone
- He was right, in the arch sense that he meant it, as a means of chiding overanxious environmentalists.
- His soulless eyes are narrowed and sullen, and his arch goatee recalls an amoral Transylvanian count.
COLLOCATIONS FROM OTHER ENTRIES the proscenium arch (=the arch over the stage where the curtain can be attached)
(=main enemy, used for emphasis)· The comic book character Lex Luthor is Superman’s arch enemy.
the proscenium arch (=the arch over the stage where the curtain can be attached) (=their main or strongest rival)· McDonald's and its arch-rival Burger King
PHRASES FROM OTHER ENTRIES
amused because you think you understand something better than other people: - At the west end is a beautiful pointed window, and at the east end three lancet windows.
- He whiled away the time by contemplating the stained glass lancet windows behind the preacher and the holy table.
- Plasteel mullions divided the narrow, high lancet windows of stained armour-glass.
- The courtyard was overlooked by the lancet windows of the manorial home itself, and a large chapel.
- The fact that this contains three lancet windows shows that this was once a building.
- There was a patch of light from the lancet window making a pattern on the floor of the chapel.
‘I think he’s in for a surprise,’ Ian said, in a somewhat arch tone.—archly adverb