1. Indicating a lack of maturity
   "infantile behaviour"
   - childish 
2. Of or relating to infants or infancy
   "infantile paralysis" 
3. Being or befitting or characteristic of an infant
   "infantile games"

See also: immature, infancy, young

• rough bristlegrass
• rough drawing
• rough fish
• rough green snake
• rough horsetail
• rough in
• rough out
• rough pea
• rough sledding
• rough trade
• rough up
• rough water
• rough-and-ready
• rough-and-tumble
• rough-cut
• rough-dry
• rough-haired
• rough-hew
• rough-leaved aster
• rough-legged hawk
• rough-sand
• rough-skinned newt
• rough-spoken
• rough-stemmed goldenrod
• rough-textured