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

See also: insidious

• sea slater
• sea slug
• sea snake
• sea spider
• sea spray
• sea spurry
• sea squab
• sea squill
• sea squirt
• sea star
• sea starwort
• sea steps
• sea swallow
• sea tang
• sea tangle
• sea trifoly
• sea trout
• sea turtle
• sea urchin
• sea wolf
• sea wormwood
• sea wrack
• sea-duty
• sea-ear
• sea-lavender family