1. In a harmfully insidious manner
   "these drugs act insidiously"
   - perniciously

See also: insidious

• one-hundredth
• one-liner
• one-man
• one-man rule
• one-member
• one-millionth
• one-night stand
• one-ninth
• one-off
• one-on-one
• one-party
• one-person
• one-piece
• one-quadrillionth
• one-quarter
• one-quintillionth
• one-seed
• one-seeded
• one-seventh
• one-sided
• one-sidedly
• one-sidedness
• one-sixteenth
• one-sixth
• one-sixtieth