1. Not methodically or according to plan
   "he dealt with his course work casually" 
2. In an unconcerned manner
   "glanced casually at the headlines"
   - nonchalantly

See also: casual

• genus Lemaireocereus
• genus lemmus
• genus Lemna
• genus Lemur
• genus Lens
• genus Lentinus
• genus Leonotis
• genus Leontideus
• genus Leontocebus
• genus Leontodon
• genus Leontopodium
• genus Leonurus
• genus Lepas
• genus Lepechinia
• genus Lepidium
• genus Lepidobotrys
• genus Lepidochelys
• genus Lepidocybium
• genus Lepidothamnus
• genus Lepiota
• genus Lepisma
• genus Lepisosteus
• genus Lepomis
• genus Leptarrhena
• genus Leptinotarsa